Yield: 16–24 bars
Prep Time: 15 minutes
Cook Time: 20 minutes
Total Time: 1 hour (includes cooling & frosting)
Ingredients
For the Bars:
2 cups all-purpose flour
2 cups granulated sugar
1 teaspoon baking soda
1 teaspoon salt
½ cup whole milk
1 teaspoon vanilla extract
2 large eggs, beaten
1 cup (2 sticks) unsalted butter
1 cup creamy peanut butter
For the Frosting:
½ cup (1 stick) unsalted butter
½ cup creamy peanut butter
2 tablespoons milk
4 cups powdered sugar
Instructions
Preheat oven to 400°F. Grease a large sheet pan (roughly 13×18 inches) or line with parchment paper.
Mix dry ingredients: In a large bowl, whisk together flour, sugar, baking soda, and salt. Set aside.
Whisk wet ingredients: In a separate bowl, combine ½ cup milk, vanilla, and beaten eggs.
Create the base: In a medium saucepan, melt 1 cup butter with 1 cup peanut butter over medium heat. Once it reaches a gentle boil, remove from heat.
Combine: Slowly stir the dry ingredients into the melted peanut butter mixture. Then add the milk/egg mixture and stir until smooth and well mixed.
Bake: Spread the batter evenly into the prepared pan. Bake for 20 minutes or until a toothpick inserted in the center comes out clean. Let cool completely in the pan.
Make the frosting: In a small saucepan, melt ½ cup butter with ½ cup peanut butter. Bring just to a boil, then remove from heat. Stir in 2 tablespoons milk, then gradually mix in the powdered sugar until smooth.
Frost the bars: Pour warm frosting over cooled bars and spread evenly. Allow to cool at room temperature until the frosting sets.
How to Store
Room temperature: Keep covered for up to 3 days.
Fridge: Lasts up to a week (let them come to room temp before serving).
Freezer: Wrap tightly and freeze for up to 2 months. Thaw overnight.