Ingredients
Method
- Preheat oven to 350°F. Line a baking sheet with parchment.
- Mix brownie mix, espresso powder, vanilla, and eggs/oil/water per box directions; fold in chocolate chips and flour if batter is too wet.
- Shape dough into a log about 12 inches long and 2–3 inches wide on the sheet; brush with beaten egg.
- Bake 20–25 minutes until set; cool 10 minutes, then slice diagonally into 3/4-inch pieces.
- Reduce oven to 300°F. Arrange slices cut-side down and bake 10–12 minutes per side until crisp.