With a rolling pin, flatten each ball into a 12-inch circle. Place cookies on a round cookie sheet oiled with olive oil. Widen the crosses with your fingers. Let cookies rise 7 hours in a warm area. Mix egg yolk with a teaspoon of water and brush each cookie with the mixture.
Place cookies on lowest rack of oven.
Bake at 300 degrees for 10 minutes. Increase heat to 350 degrees and bake 20 minutes more. Makes 2 cookies. The following recipes are pictured on B-1. Beat in egg and almond extract.