Using an eletric mixer, cream the butter, then blend in the egg yolk, sweetener, and extracts.In a separate bowl, break up the almond flour with your hands, then mix it with the remaining ingredients. Add the dry mixture to the butter mixture and stir until evenly blended. Cover and refrigerate the dough for 1 hour.
Shape the dough into 1 1/4-inch balls and place them on a large cookie sheet, evenly spaced. Refrigerate the cookies on the sheet for 15 minutes while you preheat the oven to 350.
Bake the cookies for 20 minutes. Cool them on the sheet for a minute or so, then transfer to a rack to finish cooling.