Cream together the butter and 80 grams of the powdered erythritol at a low speed until a yellowish-white colour with white ridged peaks is attained.
Next, add the egg yolk and mix at a moderate speed.
Gradually add the almond flour and mix. Shape the dough into a small ball with your hands, wrap it in cling-film or keep it in a suitable container then store in the fridge for 30 minutes.
Preheat the oven to 350° F or approximately 180° C. Remove the dough from the fridge, pinch a fist-sized ball from the dough and roll it out between two pieces of cling-film. Take care not to roll the dough for too long as this will make it difficult to cut. Cut out the shapes using the cookie-cutter. One cookie-cutter will be for the top part (star shapes with holes in them) and the other cookie-cutter for the bottom part (whole stars).
Lay the cut cookies on a baking tray and bake for about 10-12 minutes, or until slightly browned. The baking time is not set in stone and will depend on your oven. Hence feel free to check on them immediately after they hit the 7th-minute mark. The traditional recipe requires the cookies not to brown but slight browning is almost impossible to avoid when using almond flour to bake as almond flour tends to burn quicker than wheat flour.
Remove from the oven and set aside to cool on the kitchen countertop. At this point, the cookies will still be slightly soft. Take care not to fuss about with them as they break easily.
Once cooled, transfer to a plate. Using a teaspoon, transfer a small drop of low carb jam to the middle of each of the cookies without holes on them. Place the cookies with the holes on top then sieve powdered erythritol on top. Alternatively, you can sprinkle some cinnamon on top. Enjoy with a cup of tea or coffee.
Creaming means mixing butter and sugar until properly blended. Make sure the butter is cold. This assists in making it easier when cutting with the cookie-cutter. The warmer the dough, the more difficult to cut. You can return the dough to the fridge in between cutting out of the forms, just to ensure it stays cold.
The cookie dough can be made ahead of time and stored in the freezer for use later. Simply store the dough in an air-tight container in the refrigerator. It will keep for up to one year. To use, thaw on the kitchen countertop and prepare as per recipe.