Add the cocoa powder, espresso powder, salt, and baking powder, and whisk until thoroughly incorporated.
Stir in flour just until combined. Set aside.
Heat Belgian waffle iron to the "3" setting if your waffle iron has settings. Spray waffle iron generously with cooking spray {I use olive oil in a mister}.
Pour 1/4 to 1/3 cup of batter into each section of waffle iron, depending on the size.
Cook brownies for 3 minutes.
Turn brownies out onto a wire rack and continue with remaining brownies.
Dust with powdered sugar or add a scoop of ice cream and drizzle with hot fudge.
Store unused brownies in a large zipper top bag.
Notes
I found it easier to tilt the waffle iron and let the brownies fall out onto the cooling rack.
If you do not have espresso powder just leave it out. It’s there to enhance the flavor of the chocolate, not to make these brownies taste like coffee.
Store unused brownies in a large zipper top bag. It could happen, lol