Peanut Butter Sheet Cake with Peanut Butter Frosting (Ultra-Moist, Rich & Crowd-Pleasing)

Thank you so much for being here 💛 Truly. If you’re a peanut butter lover, this Peanut Butter Sheet Cake with Peanut Butter Frosting is about to steal your heart. It’s soft, rich, deeply peanut-buttery, and topped with a warm, creamy frosting that melts right into the cake—the kind of dessert people ask for again and again. I’m kicking myself every time I don’t make a double batch because it disappears fast!

This is one of those classic, no-fuss cakes that feels old-fashioned in the best way, yet completely irresistible today. Anything but boring!!

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Peanut Butter Sheet Cake with Peanut Butter Frosting Overview

This Peanut Butter Sheet Cake with Peanut Butter Frosting is baked in a large pan, making it perfect for gatherings, potlucks, holidays, or when you just need a dependable dessert that feeds a crowd. The cake is tender and moist with rich peanut butter flavor, while the frosting is smooth, creamy, and poured on warm for that signature melt-in finish.

Reasons to Love This Peanut Butter Sheet Cake

• Ultra-moist texture
• Big peanut butter flavor
• Easy, one-bowl-style cake
• Feeds a crowd
• Perfect for potlucks and celebrations

What Does This Cake Taste Like?

Rich, nutty, and buttery with a soft crumb and a sweet, creamy peanut butter frosting that soaks slightly into the cake. It’s comforting, nostalgic, and completely addictive.

Benefits of This Recipe

• Simple pantry ingredients
• Quick to make
• Travels well
• Customizable with toppings
• Always a hit

Ingredients for Peanut Butter Sheet Cake

Peanut Butter Cake

• 2 cups all-purpose flour
• 2 cups granulated sugar
• 1 tsp baking soda
• ½ tsp salt
• 1 cup unsalted butter
• ½ cup creamy peanut butter
• 1 cup water
• ½ cup milk
• 2 large eggs
• 1 tsp vanilla extract

Peanut Butter Frosting

• ½ cup unsalted butter
• ½ cup creamy peanut butter
• ¼ cup milk
• 3½–4 cups powdered sugar
• 1 tsp vanilla extract

Necessary Tools for Preparation

• Large saucepan
• Mixing bowls
• Whisk or spatula
• 10×15-inch or jelly roll sheet pan
• Offset spatula (optional)

Possible Ingredient Additions and Substitutions

• Add chopped peanuts on top for crunch
• Swirl in chocolate chips or drizzle with chocolate
• Use crunchy peanut butter for texture
• Swap milk for buttermilk for extra tenderness
• Add a pinch of cinnamon for warmth

How to Make Peanut Butter Sheet Cake with Peanut Butter Frosting Step by Step

Step 1: Preheat and Prepare

Preheat oven to 350°F (175°C). Grease and flour your sheet pan.

Step 2: Mix Dry Ingredients

In a large bowl, whisk together flour, sugar, baking soda, and salt.

Step 3: Make the Peanut Butter Base

In a saucepan, combine butter, peanut butter, and water. Bring to a gentle boil, stirring until smooth.

Step 4: Combine

Pour the hot peanut butter mixture over the dry ingredients. Stir until combined.

Step 5: Add Wet Ingredients

Stir in milk, eggs, and vanilla until smooth and well incorporated.

Step 6: Bake

Pour batter into prepared pan and bake for 20–25 minutes, until a toothpick inserted comes out clean.

How to Make Peanut Butter Frosting

Step 1: Heat the Frosting Base

In a saucepan, melt butter and peanut butter together over medium heat.

Step 2: Add Milk and Sugar

Stir in milk, powdered sugar, and vanilla until smooth and spreadable.

Step 3: Frost While Warm

Pour frosting over the warm cake and spread evenly. Let set slightly before slicing.

What to Serve with Peanut Butter Sheet Cake

This cake pairs beautifully with:

• Cold milk
• Hot coffee
• Vanilla ice cream
• Chocolate drizzle
• Fresh berries

Storage Instructions

Store covered at room temperature for up to 2 days or refrigerate for up to 5 days. Freeze slices tightly wrapped for up to 2 months.

General Information

• Prep Time: 15 minutes
• Bake Time: 25 minutes
• Total Time: 40 minutes
• Servings: 16–20

Conclusion: A Peanut Butter Lover’s Dream Cake

This Peanut Butter Sheet Cake with Peanut Butter Frosting is everything a classic dessert should be—easy, comforting, rich, and made to be shared. It’s the kind of cake that quietly becomes legendary at family gatherings and potlucks.

If you loved this recipe, try my chocolate peanut butter cake, peanut butter brownies, or classic Texas sheet cake next.

I’d love to hear how it turned out! Leave a review, share your photos on Pinterest, and let’s keep baking those irresistible, nostalgic desserts together 🥜💛

Nutritional Information (Approximate per Slice)

• Calories: 430
• Carbohydrates: 48g
• Fat: 24g
• Protein: 8g
• Sugar: 36g