Preheat the oven to 350°F and line a baking sheet with parchment paper. No one likes cookies stuck to the tray.
Whisk together the flour, cocoa, espresso powder, baking soda, and salt. Dry ingredients should play nice together.
Beat the butter, brown sugar, and granulated sugar until creamy. If it looks delicious, you’re doing it right.
Mix in the egg and vanilla extract. The dough should be smooth, thick, and irresistible.
Gradually add the dry mixture to the wet, stirring until just combined. Overmixing makes tough cookies—literally.
Scoop tablespoon-sized dough balls onto the baking sheet, spacing them 2 inches apart. Spread prevention is key.
Flatten each ball slightly with your palm. No one wants dome-shaped sandwiches.
Bake for 12 minutes, or until the edges are firm. The center should still be soft—it’ll set as it cools.
Cool on the baking sheet for 5 minutes, then transfer to a rack. Now for the fun part.