In a medium bowl, stir together crushed pretzels, flour, brown sugar, and baking soda. Stir in the melted butter. Using your fingers, press the pretzel mixture into the bottom of an ungreased 10-inch cast iron skillet. Bake in a 350 oven for 10 minutes. Carefully remove skillet from oven, leaving oven at 350 degrees.
While the crust bakes, prepare the brownie batter.
For Brownie Layer
Combine boiling water and espresso in a medium bowl. Add chocolate chips, and stir until chocolate melts; cool slightly. Stir in melted butter, vanilla, egg, and egg white.
In a large bowl, combine flour, sugar, cocoa, baking powder, and next salt, stirring with a whisk or sturdy fork. Add coffee mixture to dry ingredients, stirring just until moist. Carefully spread batter over the top of the baked pretzel crust, smoothing the top. Decorate the top of the brownie with whole pretzels, lightly pressing the pretzels into the brownie batter.
Bake at 350° for 20-25 minutes or until a wooden pick inserted in center comes out clean. Cool in pan on a wire rack. To serve, cut wedges, like pie wedges.
I put that it serves 8, thinking that it's pretty easy to cut this into 8 wedges, but you'll probably get more than 8 servings out of them. I could see getting 12 servings here, easily.
Find this and other delicious recipes at Life Currents https://lifecurrentsblog.com