Preheat and prep. Heat the oven to 350°F (175°C).
Line a baking sheet with parchment paper so the cookies don’t stick.
Mix the wet ingredients. In a medium bowl, whisk the egg, melted butter, vanilla, and almond extract until smooth and glossy.
Combine dry ingredients. In a separate bowl, stir together almond flour, sweetener, baking powder, and salt. Break up any lumps with a fork.
Bring the dough together. Add the dry mixture to the wet and stir until a soft dough forms. If adding chocolate chips or zest, fold them in now.
The dough should be thick but scoopable.
Chill briefly. Cover and refrigerate for 10–15 minutes. This helps reduce spread and improves texture.
Portion and shape. Scoop tablespoon-sized balls and place them 2 inches apart on the baking sheet. Gently flatten to about 1/2 inch thick.
Press a few sliced almonds on top for crunch.
Bake. Bake for 9–12 minutes, until the edges are just turning golden. For softer centers, pull them at the first sign of browning; for crisper cookies, add 1–2 minutes.
Cool completely. Let the cookies cool on the tray for 10 minutes, then move them to a wire rack. They firm up as they cool, so resist the urge to move them too soon.