Step 1

Preheat oven to 350°F. Line an 8x8 baking pan with foil or parchment paper. Lightly grease the foil/parchment.

Step 2

In a medium bowl combine cocoa powder, powdered sugar, flour, and salt. Set aside.

Step 3

In a large bowl combine butter and granulated sugar, whisk briefly, then allow the mixture to sit at room temp for 5 minutes. After 5 minutes, whisk the mixture vigorously for about 30 seconds. Add eggs, water, and vanilla extract. Whisk until well combined.

Step 4

Add the dry ingredients to the wet ingredients and use a rubber spatula or wooden spoon to stir the mixture until it is glossy and well combined. Remove ⅓ cup of brownie batter and set it aside.

Step 5

Add chocolate chips, peanut butter chips, and peanut butter cups to the remaining batter and stir gently. Pour the batter into the prepared pan and spread into an even layer.

Step 6

Using two spoons, dollop small portions of the peanut butter and the reserved brownie batter all over the top. Use the tip of a sharp knife to swirl the brownie batter and peanut butter together*. Don’t swirl too deep; you are mostly just making visible swirls in the top layer.

Step 7

Bake for 28-33 minutes. The brownies should be underbaked just slightly, but not jiggle in the center. If you insert a toothpick into the center it should come out with moist fudgy crumbs, but no thin, raw batter. Place the pan on a wire rack to cool.