1-First, preheat your oven to 300°F (150°C) and line a baking sheet with parchment paper to make cleanup a snap. In a medium bowl, whisk together the flour, cocoa powder, cornstarch, espresso powder if you’re using it, salt, and baking soda until everything’s well mixed. That dry blend is your foundation for those crispy edges!

2-Next, in another bowl, whisk the egg whites, sugar, and vanilla until they’re nice and foamy this step really helps with that light texture. Now, add the dry ingredients to this wet mixture and stir until smooth; it’s that simple mix that keeps things from getting too complicated. Stir in the melted butter to bring it all together, then spread the batter thinly on your prepared baking sheet using an offset spatula for that extra crisp finish.

3-Bake it for 25 minutes, then transfer the sheet to a wire rack to cool completely patience here is key! Once it’s out, cut the crisps into shapes right away while they’re still soft, as they’ll harden up as they cool. For dietary swaps, like making it vegan, use flax eggs in place of egg whites and plant-based butter during the mixing stage to keep the texture spot-on.