0.5cuproasted peanuts, choppedoptional for topping
Instructions
Preparation Steps
Heat oven to 350°F. Grease a 13×18-inch rimmed sheet pan and line with parchment.
Whisk flour, sugar, baking soda, and salt in a large bowl.
Melt butter, peanut butter, and water in a saucepan over medium heat. Whisk until smooth, then cool 2 minutes.
Pour the warm peanut butter mixture into the dry ingredients and stir until mostly combined.
Whisk eggs, buttermilk, and vanilla together, then fold into the batter until smooth.
Spread batter evenly in the pan. Tap the pan once to release bubbles.
Bake 20–23 minutes, until the center springs back and a toothpick comes out clean.
Start the frosting during the last 5 minutes of baking. Heat butter, peanut butter, and milk in a saucepan until it gently bubbles.
Remove from heat. Whisk in vanilla and salt, then beat in powdered sugar until glossy and spreadable.
Pour warm frosting over the hot cake. Spread quickly and sprinkle with peanuts, if using.
Cool until set, about 30 minutes. Slice into squares and serve.
Notes
Try swirling 1/4 cup warm jelly over the frosting for a PB&J twist, or finish with a drizzle of melted chocolate. No buttermilk? Mix 1/2 cup milk with 1 1/2 tsp lemon juice and rest 5 minutes. Store covered at room temperature up to 3 days or refrigerate for a fudgier bite.This recipe is an original creation inspired by classic Peanut Butter Sheet Cake Bliss flavors. All ingredient ratios and instructions are independently developed.