Lunchroom Chocolate Peanut Butter Bars.

1. Preheat the oven to 350 degrees F. Line a 9x13 inch baking dish with parchment paper.2. In a microwave safe bowl, melt together the butter and 1/2 cup peanut butter, stirring every 30 seconds until melted. Stir in the brown sugar, sugar, eggs, and vanilla. Add the flour, baking powder, and salt. 3. Press/spread the dough out into the prepared dish. Transfer to the oven and bake for 18-22 minutes, until just set in the center. Remove from the oven and dollop tablespoon size spoonfuls of the peanut butter over the bars, lightly spreading the peanut butter in an even layer. Let cool completely. 4. To make the frosting. Add the butter, 2 cups powdered sugar, cocoa powder, vanilla, and 1/4 cup warm milk to the bowl of a stand mixer. Beat until smooth, adding additional warm milk until the frosting becomes thicker, but still drizzly. Taste, adding more sugar if needed. Spread the frosting over the bars. Let set for 1-ish hour...or slice, snack, and enjoy!