Peanut Butter Sheet Cake with Peanut Butter Frosting

💕😋 Peanut Butter Sheet Cake with Peanut Butter Frosting 😋💕

When peanut butter lovers dream of dessert heaven, this sheet cake checks all the boxes: rich peanut butter flavour, a simple (but show‑stopping) frosting, and a no‑fuss format that feeds a crowd. Whether you’re baking for a birthday, potluck or just to treat yourself, this cake comes together quickly and delivers big time. 🍞🍯

Introduction: Why you’ll fall in love with this cake

There are desserts that require time, technique and special equipment—and then there are ones that feel effortless yet taste luxurious. This peanut butter sheet cake lands in the latter category. With a boxed cake mix base plus a few extra enhancements, it becomes something extraordinary. Then topped with a creamy, decadent peanut butter frosting and sprinkled with chopped roasted peanuts (and optionally flaky sea salt), you’ve got a dessert that sings.

As Chef Ina Garten would say: “The key is to pick good quality ingredients, keep the process simple, and let the flavors shine.” And indeed, this cake is all about letting peanut butter be the star—but with smart choices so the texture, moisture and finish are all on point.

In this article you’ll find a detailed ingredient overview, step‑by‑step method, expert tips, health & safety notes, a nutrition table, FAQs and more. If you’d like to link to deeper reading on dessert techniques (for example on www.freshtonerhungar.com), I’ll include internal links too for you.

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Ingredients & Prep

Here’s the full ingredient list, exactly as you provided — with a bit of commentary to clarify measurements and options.

For the Peanut Butter Cake Base

• ½ cup (1 stick) salted butter, cut into cubes
• ¾ cup creamy peanut butter (natural or conventional—avoid oily separates)
• ⅓ cup whole milk (any dairy or unsweetened plant milk works)
• ⅓ cup neutral oil (canola, vegetable, or grapeseed)
• 1 tsp pure vanilla extract
• 2 large eggs, room temperature
• 1 box (15.25 oz) golden yellow cake mix (for example, Duncan Hines Golden Butter; see note for newer 13.75‑oz boxes)

For the Peanut Butter Frosting

• ½ cup (1 stick) salted butter
• ½ cup creamy peanut butter
• ⅓ cup whole milk
• 1 tsp vanilla extract
• 16 oz (≈ 3¾ cups) powdered sugar, sifted
• Pinch of fine sea salt (to balance sweetness)

Finish & Garnish

• ½ cup dry‑roasted peanuts, finely chopped & lightly toasted
• Optional: flaky sea salt for garnish

**Note:** If your cake mix size is smaller (e.g., newer 13.75 oz boxes), adjustments may be needed. One blog notes adding about ¼ cup all‑purpose flour when using a smaller box to keep texture consistent. :contentReference[oaicite:0]{index=0}

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Step‑by‑Step Method

1. Preheat & prepare pan

Preheat your oven to 350 °F (≈ 177 °C). Lightly grease a 15 × 10″ jelly‑roll pan **or** a 13 × 9″ baking dish. For easier removal, you can line the pan with parchment paper (optional but helpful for lifting later).

2. Make the cake base batter

In a large microwave‑safe bowl, combine the butter, ¾ cup peanut butter and the milk. Microwave on HIGH for about 60 seconds (assuming ~1100 W) until the butter is melted and everything is smoothly blended. Stir vigorously until glossy.

Then stir in the oil and vanilla extract.

Add the 2 eggs (room temperature helps for even mixing). Whisk lightly in the center just to break the yolks, then fold them into the peanut‑butter mixture until fully blended (about ~30 seconds). The mixture will be thick, glossy and slightly elastic.

Finally, add the box of cake mix and stir vigorously (about 45 seconds) until no lumps remain and the batter is smooth. According to one recipe, the batter will appear thick and “slightly elastic”. :contentReference[oaicite:1]{index=1}

3. Bake the cake

Pour or spread the batter evenly into your prepared pan, smoothing the corners with a damp offset spatula if desired.

For the 15 × 10″ pan: Bake about 13‑15 minutes.
For the 13 × 9″ pan: Bake about 19‑21 minutes.

You’ll know it’s done when a toothpick near the center comes out with moist crumbs (not wet batter). **Do not overbake** — the cake will firm up as it cools. :contentReference[oaicite:2]{index=2}

4. Make the frosting while cake cools (~15 minutes)

In a clean microwave‑safe bowl, combine the butter, ½ cup peanut butter and the milk. Microwave ~50 seconds (or until butter melted). Stir until smooth.

Then whisk in the vanilla extract, the sifted powdered sugar and the pinch of sea salt. Stir until creamy and pourable (like warm caramel). If it has become too thick, add milk ½ tsp at a time until you reach the proper spreadable consistency. :contentReference[oaicite:3]{index=3}

5. Frost & garnish

When the cake has cooled for about 15 minutes (so it’s slightly warm, not hot), pour the warm frosting evenly over the cake. Tilt the pan gently as needed to spread edge‑to‑edge.

Immediately sprinkle the chopped toasted peanuts on top and press lightly so they adhere. If you like, sprinkle a light dusting of flaky sea salt for an extra flavour contrast.

6. Cool, slice & serve

Allow the cake to cool uncovered for about 1 hour at room temperature so frosting sets and slices cleanly. If you plan to gift it or transport it, you can refrigerate for about 30 minutes to firm it up further before slicing.

Then slice into squares, serve and enjoy! 😋💕

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Health Tips & Safety Considerations

While this is undeniably a dessert and an indulgent one, here are some expert tips to make it a bit smarter — plus important safety considerations.

• **Quality of peanut butter**: Some natural peanut butters separate (oil rises) and can cause issues in baking textures. One frosting‑recipe warns natural peanut butter might make texture “weird” unless very well stirred. :contentReference[oaicite:4]{index=4}
• **Room‑temperature eggs**: Using eggs at room temperature helps them incorporate more evenly in batter, giving better rise and crumb. Many bakers emphasise this for cakes. :contentReference[oaicite:5]{index=5}
• **Avoid overbaking**: Overbaked cakes become dry quickly. Particularly with a moist batter like this peanut butter one, pulling it out when the toothpick shows moist crumbs is key. :contentReference[oaicite:6]{index=6}
• **Frosting while warm**: The cake should be slightly warm (but not hot) when you pour the frosting — if the cake is too cool, the frosting may set too quickly and not glide smoothly; if too hot, frosting can melt or slide off. One source emphasises waiting 15 minutes before frosting. :contentReference[oaicite:7]{index=7}
• **Storage & make‑ahead**: This cake stores well — many recommend keeping covered at room temperature for 3‑4 days, or in the fridge if you prefer. It also freezes well (especially UNFROSTED shells or slices individually wrapped). :contentReference[oaicite:8]{index=8}
• **Allergy/nut‑safety**: Since this is heavy on peanut butter + peanuts, ensure your guests don’t have peanut allergies. Also, when using salted butter or salted peanuts, be mindful of added sodium.
• **Portion control**: Because of the richness (butter, peanut butter, sugar, oil), keep serving sizes moderate if you are watching calories or fat. Pairing with a simple fresh fruit or lightly sweetened whipped topping can help balance.

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Nutrition & Health Benefits Table

Here’s an approximate nutritional breakdown *per slice* (assuming 16 slices from the full 15 × 10″ pan) using standard ingredients. Actual values vary based on brands and portions.

**Health benefit comments:**

• Peanut butter provides flavour *and* some healthy fats (monounsaturated) and plant‑protein. While this cake is rich, the peanut butter adds a bit more nutritional value than dessert made purely of sugar and white flour.
• Milk (or plant‑milk) contributes calcium and vitamin D (depending on fortification).
• That said: the dessert is high in saturated fat, sugar and refined carbs. Best enjoyed as a treat and balanced with overall healthy meals (vegetables, lean protein, whole grains) the other times.

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Insights from the Expert Chef (featuring Ina Garten)

Here’s a crafted “chef’s take” (inspired by master entertainer Chef Ina Garten) on how she might approach this cake:

“First, while you’re melting butter and peanut butter, be sure to use good‑quality butter and a creamy peanut butter that isn’t too oily or separated. Let the mixture stir until glossy. Then pour that warm mixture into the cake batter so the flavours blend. Later, when you prepare the frosting, don’t rush: the cake must be just warm — not hot nor completely cold — when you pour the frosting. That’s how you get that smooth, slightly shiny surface and those crisp edges. And finally, sprinkle the chopped toasted peanuts and a little flaky sea salt for the pop of texture and flavour. Simple, elegant, irresistible.”

**Chef’s Pro Tips:**

• Use *salted* butter if you like a little contrast between sweet and savoury. The pinch of sea salt in the frosting helps too.
• For extra even slicing, use a large sharp knife dipped in hot water and wiped dry between cuts — this helps clean edges on a rich frosting‑topped sheet cake.
• If you’re making ahead for a gathering, bake the cake a day ahead, cover it loosely, then gently warm or rest to room temp before applying the frosting. That way you can focus on the garnish when guests arrive.
• Consider a variation: swirl chocolate ganache or drizzle melted dark chocolate over the finished cake for a “peanut butter + chocolate” twist. One blog suggests chocolate shavings or mini peanut‑butter cups as a garnish. :contentReference[oaicite:9]{index=9}

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10 Frequently Asked Questions (FAQs)

1. Can I use a different size cake pan?
   Yes — this recipe is set for a 15×10″ sheet or a 13×9″ baking dish. If you scale down to a smaller pan you’ll need to reduce bake time. One source notes if you use a smaller cake‑mix box (13.75 oz instead of 15.25 oz) you may add ~¼ cup flour. :contentReference[oaicite:10]{index=10}
2. Can I use natural peanut butter (the kind that separates)?
   Possibly—but some recipes caution that natural peanut butter can cause a “weird” texture in the frosting because of extra oil/separation. :contentReference[oaicite:11]{index=11} If you do use it, stir well first and consider slightly reducing added oil/milk.
3. What if I don’t have a microwave for melting butter/peanut butter?
   You can use a small saucepan on the stovetop: melt butter and peanut butter in medium heat, stir until smooth, then remove from heat and proceed. One blog describes this method. :contentReference[oaicite:12]{index=12}
4. Can I make this gluten‑free?
   If you use a gluten‑free yellow cake mix and ensure all other ingredients are certified gluten‑free, yes — although texture may vary. Some readers successfully swap flour / mix base for gluten‑free 1:1 flour for peanut butter sheet cakes. :contentReference[oaicite:13]{index=13}
5. How far in advance can I bake and frost?
   You can bake the base ahead of time and store (well‑covered) at room temperature a day before. Frosting is best poured when cake is slightly warm. If you frost ahead, keep well covered and chill or serve soon. Cake and frosting freeze well too (especially un‑frosted or individual slices) — one site says freeze unlidded for ~1 hour then wrap and freeze up to 2‑3 months. :contentReference[oaicite:14]{index=14}
6. Why did my frosting run off the cake?
   Possible reasons: The cake was too warm (so frosting slid), or the frosting was too thin. Make sure cake is only warm (not hot). Also ensure frosting consistency is correct (pourable but thick). If frosting becomes too thin, chill the cake and/or add a bit more powdered sugar. :contentReference[oaicite:15]{index=15}
7. Can I substitute the garnish with something else?
   Yes — chopped roasted peanuts are classic, but you could also add crushed peanut‑butter cups, chocolate nibs, salted caramel drizzle or even toasted coconut flakes for a twist. One blog suggests chocolate shavings or crunchy peanut butter in place of chopped peanuts. :contentReference[oaicite:16]{index=16}
8. My cake is dry — what went wrong?
   Likely overbaked. Because this batter is rich and moist, it can become dry if baked too long. Watch the toothpick test: you want moist crumbs, not wet batter. Also using room temperature eggs and good milk helps. :contentReference[oaicite:17]{index=17}
9. Storage: room temperature or fridge?
   You can store at room temperature, covered with plastic wrap or foil, for about 3‑4 days. In warmer climates or if your frosting has more milk/dairy, you may prefer refrigerating. Before serving from fridge, allow to come to room temperature for best texture. :contentReference[oaicite:18]{index=18}
10. Is this cake suitable for a large crowd or events?
    Yes — this sheet cake format is ideal for feeding many with minimal fuss. It’s also easy to slice into varying sizes. One blog calls it “moist, fudgy … perfect for any type of gathering.” :contentReference[oaicite:19]{index=19}

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Related Reading & Internal Links

For more dessert inspiration and technique articles, check out these relevant pieces from www.freshtonerhungar.com:

• How to Make Smooth Pastry Cream: A Beginner’s Guide
• Choux Pastry 101: Techniques & Troubleshooting
• Mini Cream Puffs: Party‑Friendly Dessert Ideas

These articles complement this recipe by giving you more depth on other dessert formats, so you can build a full dessert‑menu if desired.

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Final Thoughts

This peanut butter sheet cake isn’t just another dessert — it’s a standout. From the first bite of moist, peanut‑buttery cake to the sweet and slightly salty frosting, it hits all the notes. Whether you’re a devoted peanut butter fan or just looking for a crowd‑pleaser, this one delivers.

Take your time with the key moments — melting the butter/peanut butter mixture so it’s smooth; pouring the frosting when the cake is slightly warm; topping with chopped peanuts and sea salt for texture and contrast. These small details elevate it.

Make it your own: use crunchy peanut butter for more texture, or add a drizzle of dark chocolate for a peanut‑butter‑cup vibe. Serve it with a cold glass of milk, a cup of coffee, or simply on its own. It’s indulgence at its finest. 🍫🥜

Happy baking — and enjoy every gooey, nutty, delicious slice! 😋💕