Prepare the Dry Mix: In a medium bowl, sift together the almond flour, unsweetened cocoa powder, espresso powder, and sea salt. Whisk well to ensure there are no lumps and set aside.

Cream the Butter: In a large mixing bowl, use an electric hand mixer to beat the softened butter and granulated sweetener on medium speed. Continue for about 2 minutes until the mixture is pale and fluffy.

Add Flavors: Scrape down the sides of the bowl. Add the vanilla extract and the first amount of peppermint extract (1/4 teaspoon) to the butter mixture. Mix briefly to combine.

Combine and Fold: With the mixer on low, gradually add the dry flour mixture to the wet ingredients in two batches, mixing until just combined. Gently fold in the beaten egg white with a spatula until a cohesive dough forms.

Chill the Dough: Place the dough between two large sheets of parchment paper. Roll it out to approximately 1/4-inch thickness. Transfer the rolled dough (still in the paper) to the freezer for 15-20 minutes to firm up.

Cut and Bake: Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper. Remove the dough from the freezer, peel off the top paper, and use a 2-inch round cutter to punch out cookies. Place them on the baking sheets 1 inch apart. Re-roll scraps and repeat (chill again if dough gets too sticky). Bake for 11-12 minutes.

Cool: Let cookies cool on the baking sheet for at least 10 minutes (they solidify as they cool), then transfer to a wire rack to cool completely before dipping.

Dip: Place the chocolate, coconut oil, and remaining 1/2 teaspoon peppermint extract in a microwave-safe bowl. Microwave in 30-second intervals, stirring in between, until smooth. Using a fork, dip each cooled cookie into the chocolate, tapping off the excess, and place onto a parchment-lined tray.

Set: Refrigerate the coated cookies for 15 minutes until the chocolate shell hardens.