01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together the gluten-free flour blend, almond flour, baking soda, salt, cocoa powder, and espresso powder in a medium bowl until well blended.
03 - Beat the softened butter, granulated sugar, and brown sugar together in a large bowl until light and fluffy, approximately 2–3 minutes.
04 - Add the egg and vanilla extract to the butter mixture. Beat until fully incorporated and smooth.
05 - Gradually mix in the dry ingredients to the wet mixture, stirring until a soft, uniform dough forms.
06 - Scoop tablespoon-sized portions of dough onto the prepared baking sheets, leaving approximately 2 inches of space between each cookie.
07 - Bake for 10–12 minutes until edges are set and centers appear slightly underbaked for optimal chewiness.
08 - Let cookies rest on the baking sheet for 5 minutes, then transfer to a wire rack to cool entirely.
09 - Melt the dark chocolate and coconut oil together in a microwave-safe bowl, heating in 20-second intervals and stirring until smooth and glossy.
10 - Drizzle the melted chocolate over the cooled cookies using a spoon or piping bag. Allow chocolate to set completely before serving.