Chocolate Peanut Butter Sheet Cake
Rich chocolate cake layered with creamy peanut butter frosting and studded with chocolate chips and salted peanuts. This showstopping dessert combines deep cocoa flavor with nutty sweetness, making it perfect for potlucks, celebrations, or feeding a crowd. The simple one-bowl cake method means minimal cleanup while delivering bakery-quality results. What sets this version apart is the peanut butter frosting base that beyond standard chocolate, creating a sophisticated flavor pairing.
Ingredients
- 2 cup all-purpose flour, siftedwhole wheat flour1:1higher-fiber
will increase density
- 1 ½ cup sugar, granulated
- 1 cup water, room temperature
- ½ cup unsweetened cocoa powder, sifted
- ½ cup butter, softened
- 3 large eggs, room temperature
- 1 ¼ teaspoon baking powder
- 1 teaspoon baking soda
- 1 teaspoon salt
- 1 teaspoon vanilla extract
- 1 cup mini semi-sweet chocolate chips
- ½ cup peanut butter, creamy
- 3 cup powdered sugar, sifted
- 3 tablespoon half and half, or to taste for consistency(optional)
- ½ cup mini semi-sweet chocolate chips
- ½ cup peanuts, chopped, salted
Instructions
- 1
Preheat oven to 350F. Grease and flour a 13x9-inch baking pan.
- 2
Combine flour, sugar, water, cocoa, softened butter, eggs, baking powder, baking soda, salt, and vanilla in a large bowl.
- 3
Beat at low speed while scraping bowl often until moistened.
- 4
Beat at high speed while scraping bowl often until well mixed.
- 5
Fold in chocolate chips.
- 6
Pour batter into prepared pan.
- 7
Bake 30-40 minutes until a toothpick inserted in the center comes out clean.
- 8
Cool cake completely before frosting.
- 9
Combine butter and peanut butter in a medium bowl.
- 10
Beat at high speed while scraping bowl often until light and creamy.
- 11
Add powdered sugar and beat at low speed.
- 12
Gradually add half and half while scraping bowl often until smooth and spreadable.
- 13
Frost cooled cake.
- 14
Sprinkle chocolate chips and chopped peanuts over frosting.
Tips
For easier frosting, use room-temperature peanut butter and butter so they blend smoothly without lumps. This ensures a silky, spreadable consistency.
Insert toothpick in the thickest part of the cake near the center for the most accurate doneness check. Slight moist crumbs are fine; wet batter is not.
Add half and half gradually to frosting; you may not need the full 4 tablespoons. Consistency matters for frosting application.
Good to Know
Store covered at room temperature up to 3 days. Refrigerate if frosting contains dairy half and half; keep 4-5 days covered.
Bake cake layer 1 day ahead and wrap unfrosted. Prepare frosting day-of and apply within 2 hours of serving for best texture.
Serve at room temperature. Cut into 12-15 squares. Pairs well with coffee, milk, or vanilla ice cream.
Common Mistakes
Do not overmix batter after adding chocolate chips to avoid overdeveloped gluten and tough cake.
Do not frost warm cake; it will cause frosting to melt and slide off.
Do not skip scraping the bowl during beating to ensure even incorporation and avoid lumps.
Substitutions
Dairy-Free Swaps
Vegan Options
Nut-Free Alternatives
General Alternatives
FAQ
Can I make this cake in a round pan instead?
Yes. Use two 9-inch round pans and reduce baking time to 25-30 minutes. Check with a toothpick early as thinner layers bake faster. Fill and frost between layers.
What if I don't have semi-sweet chocolate chips?
Substitute milk chocolate, dark chocolate, or chopped chocolate bars in equal amounts. Dark chocolate will add deeper cocoa notes; milk chocolate will be sweeter. Chips and chunks both work fine.
Can I freeze this cake?
Yes. Wrap unfrosted cake tightly in plastic wrap and freeze up to 3 months. Thaw at room temperature before frosting. Frosted cake freezes 1-2 months; thaw slowly to prevent frosting damage.