Pre-heat oven to 350° (180° celsius). Line cookie sheets with parchment paper.
In a medium bowl whisk together, the flour, zest and salt, set aside.In a large bowl beat at medium speed the butter and sugar until light and fluffy, approximately 2 minutes, then add the egg yolks and vanilla, beat until just combined. Stir in the flour mixture with a wooden spoon or mix on low speed just until combined. Move to a flat surface and form into a compact smooth dough.
Remove pieces of dough and roll into (approximate) 1 inch (2cm) balls.
Place egg whites in a small bowl and the finely chopped almonds in another bowl. First roll balls in egg whites and then in the almonds, place them on prepared cookie sheets about one inch apart. Gently make an indentation with your thumb or the bottom of a wooden spoon in every ball. Bake for approximately 15 minutes, at the halfway point check to see if the centres have puffed up, if yes, then using the end of a wooden spoon gently indent again. Remove from oven when done and indent again with wooden spoon if needed.
Remove to cool on a wire rack. When cool fill withItalian Pastry Cream or your favourite filling. Enjoy!
Lemon Thumbprint Cookies https://anitalianinmykitchen.com/thumbprint-cookies/