- Preheat oven to 350° F.
- Cream the butter until it is light.
- Gradually add the powdered sugar, creaming well after each addition.
- Add the egg yolks one at a time, salt and the lemon juice, and zest.
- Gradually add the flour and stir or knead the dough until blended. Chill for at least 2 hours.
- Roll the dough with lightly floured hands into uniform balls the size of large marbles. Press an indentation into each ball with your little finger. Brush on the egg yolk and sprinkle the tops with almonds and sugar.
- Bake for about 10 minutes or until the balls are golden brown.
- When ready to serve fill the indentations with your choice of jam.