For the eggnog cookies, first knead butter, 100 g powdered sugar, salt and lemon zest with dough hook until smooth. Stir in the egg. Knead in flour, starch and ground almonds. Chill in plastic wrap for 2 hours.
Roll out dough to 3 mm thickness, cut out cookies with round, serrated cutters, cut out a smaller circle from half of the cookies. Bake at 180 degrees for 8-10 minutes.
Halve almonds, roast in pan without fat. Dust the rings with 10 g of powdered sugar. Mix the remaining powdered sugar with egg liqueur, spread on the center of the whole cookies. Place rings on top, place 1 almond in the center of each and let the eggnog cookies dry.