Using a stand or hand mixer, cream the butter and confectioners sugar until light and fluffy, 4-5 minutes. Scrape down the bowl with a spatula. Beat in the yolks and almond extract, until smooth. In a medium bowl mix all-purpose flour, almond meal and salt, combine with the butter mixture, mix well. Form the dough into a disk, wrap in a plastic and transfer into refrigerator for 1 hour. Preheat oven to 350 F. Lay cookie sheet with a parchment paper. Form 1 tablespoon of dough into a small balls; place on a cookie sheet. Chill 10-15 minutes. Press in the skinless almonds into the center of the cookies, or use your thumb to create an imprint, you could fill them with your favorite jam later. Bake the cookies at 350 F for 17-20 minutes. Cool cookies on racks, dust with a confectioners sugar (optional), then fill with jam.