Peanut Butter Sheet Cake

Soft peanut butter cake that's good enough to eat plain, with an optional fudge frosting if you want to go all in.

One bowl for the dry stuff, one pan for the wet, and it's in the oven in 20 minutes. I made mine without frosting and cut it into squares. It's more of a snack cake that way, and it didn't need anything else. If you want to dress it up, there's a peanut butter fudge frosting you pour on while it's warm.

Prep: 20 min · Cook: 22–26 min · Serves: 12

Ingredients

For the cake

• 1 1/4 cups (156g) all-purpose flour

• 1 cup (200g) granulated sugar

• 1/4 tsp salt

• 1/4 tsp cinnamon

• 1/2 tsp baking soda

• 5 tbsp (70g) unsalted butter

• 3 tbsp (48g) creamy peanut butter

• 1/2 cup (115ml) low-fat buttermilk

• 1 large egg

For the frosting (optional)

• 6 tbsp (85g) unsalted butter

• 1/4 cup (64g) creamy peanut butter

• 3 tbsp (45ml) buttermilk

• 2 cups (240g) powdered sugar

• 1/2 tsp vanilla extract

Instructions

1. Preheat oven to 350°F (175°C / Gas Mark 4). Grease a 9x13-inch quarter sheet pan (1-inch sides) with cooking spray.

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

3. In a small saucepan over low heat (or a microwave-safe dish), melt the butter and peanut butter together until smooth.

4. Whisk the buttermilk and egg into the melted butter mixture until smooth.

5. Pour the wet ingredients over the dry ingredients and stir until combined.

6. Pour into the prepared pan and bake 22–26 minutes. The edges brown more than the middle, and it won't pull away from the pan, so check it with a toothpick. It's done when the toothpick comes out clean.

7. Optional frosting: while the cake is still warm, make the frosting. Put the butter, peanut butter, buttermilk, and powdered sugar in a small saucepan and heat over low until it's melted and pourable.

8. Stir in the vanilla. Pour the warm frosting over the warm cake, spread it to the edges, and let it set before slicing. Skipping the frosting? Just let the cake cool and cut it into squares.

Notes

• The frosting is optional. I skipped it and the cake was great on its own. If you do frost it, do it warm, because warm frosting on a warm cake spreads easily and sets smooth.

• No quarter sheet pan? A quarter sheet pan is 9x13 inches with 1-inch sides. A regular 9x13 baking dish works too, and the cake will just be a little thinner.

• No buttermilk? Stir 1/2 tbsp lemon juice or white vinegar into 1/2 cup milk and let it sit 5 minutes.

Adapted from Dessert for Two.

Peanut Butter Sheet Cake Recipe.pdf

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