In a medium bowl, stir together the flour and sugar. Cut in butter until a mealy consistency is reached. Add water, almond extract, and egg yolk; mix by hand and knead into a smooth ball. Wrap and refrigerate dough for up to 1 hour.
Preheat oven to 350 degrees F (175 degrees C). Roll pieces of dough into 1 inch balls and press down into the cookie molds or small tart molds. Press so dough is all of the way up the side of the molds, then prick with a fork to keep them from puffing up and deforming during baking.
Bake cookies for 15 to 20 minutes, until golden brown. Cool cookies in molds on a wire rack for 10 minutes before carefully removing to cool completely.