Step 1

In medium bowl, whisk together the flour, cocoa powder and salt. Whisk to break up any lumps in the cocoa powder.

Step 2

In a medium saucepan over low heat, melt the butter and espresso powder. Remove from the heat.

Step 3

Stir in the chocolate chips until fully melted and smooth. If there is chocolate that hasn’t melted, put back on low heat and stir until melted.

Step 4

Whisk in the granulated sugar and brown sugar.

Step 5

Whisk in the eggs, one at a time, stirring after each addition. Whisk in the vanilla.

Step 6

Fold in the flour mixture, stirring until just combined. Scrape down the sides and bottom of the bowl with a spatula to ensure everything is fully mixed.

Step 7

Fold in half of the chopped peanut butter cups.

Step 8

Spread the brownie batter into the prepared pan in an even layer.

Step 9

Warm the peanut butter in the microwave for 20-30seconds until it has softened and thinned. It should be slightly liquidy and have the consistency of caramel sauce.

Step 10

Dollop spoonfuls of the peanut butter over the brownie batter. Create swirls in the batter with a toothpick.

Step 11

Sprinkle the remaining half of the chopped peanut butter cups on top of the brownies.

Step 12

Bake for 25-35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Step 13

Let the brownies cool to room temperature, or just warm, then cut into squares and serve.