These brownies have a sweet, salty, crunchy bottom that's made out of pretzels, butter, and sugar. So, basically heaven. I used my favorite brownie batter that always bakes up thick and fudgy. It's dotted with dark chocolate chips for extra chocolate oomph. And, just for fun, I swirled some melty peanut butter over the top of things.
To make the crust, place the pretzel sticks into a food processor or blender and process until you have fine crumbs. Mix with the melted butter and sugar. Press into a foil lined 9x13 baking dish.
To make the brownies, in small saucepan over low heat, melt butter completely. Stir in sugar and continue cooking for 1-2 minutes, stirring constantly. Do not allow sugar mixture to boil.
Pour butter mixture into a large bowl or stand mixer. Beat in cocoa powder, eggs, salt, baking powder, espresso powder, and vanilla extract. Mix until well combined.
Stir in the flour until just combined.
Spread over the pretzel crust (batter will be very thick and sticky). Melt the peanut butter in a microwave safe dish. Pour over the brownie batter and swirl into the batter with a knife.
Bake for about 30 minutes, until a tester comes out mostly clean. The edges should be set and the center should still look slightly moist, but not uncooked.