In a bowl, add the almond flour, coconut flour, cacao powder, baking soda, xanthan gum, and sea salt. Set aside.

In a separate bowl, with an electric mixer on medium speed, beat the butter and erythritol sweetener until fluffy, for 3 minutes. Add the egg and vanilla. Mix until well incorporated.

Reduce the mixer speed to low, and gradually add the flour in two batches. Fold in the chocolate chips. Cover the bowl with plastic wrap and refrigerate for 1 hour.

Preheat the oven to 350°F. Line 2 baking sheets with parchment paper.

With your hands slightly wet, scoop out about 1½ tablespoons of dough and roll it into a ball. Arrange the ball on the prepared baking sheet. Repeat with the remaining dough. Sprinkle the almond flakes on top of the cookies. Bake the cookies for 9 to 10 minutes, until crisp around the edges. Remove from the oven and let the cookies cool on the baking sheet for 5 minutes.