01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - Whisk together almond flour, erythritol, cocoa powder, espresso powder, baking soda, and salt in a large bowl.
03 - Mix peanut butter, egg, melted butter, and vanilla extract in another bowl until smooth.
04 - Add wet ingredients to dry ingredients and stir until a soft dough forms. Fold in chocolate chips if using.
05 - Scoop dough into 1-tablespoon portions and roll into balls. Place on the prepared baking sheet, spacing about 2 inches apart.
06 - Flatten each ball gently with a fork, making a crisscross pattern.
07 - Bake for 10–12 minutes, until edges are just set.
08 - Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.