Melt the butter or coconut oil in a microwave-safe bowl in 20-second increments until fully melted.

Combine almond flour, powdered sugar (or erythritol), baking soda, and salt in a mixing bowl and whisk until blended.

Add lemon zest, lemon juice, and vanilla extract to the melted mixture, then combine with the dry ingredients.

Wrap the dough in plastic wrap and refrigerate for at least 30 minutes for a chewier texture.

Preheat the oven to 325°F (163°C) and line a baking tray with parchment paper.

Form 1-inch balls from the chilled dough and place them on the baking tray, optionally rolling in powdered sugar or erythritol.

Bake the cookies for 10 minutes until lightly golden around the edges.

Press each cookie down gently with the back of a spoon as soon as they come out of the oven.

Let the cookies cool on the baking tray for 5–10 minutes before transferring them to a wire rack.