Beat butter at medium speed of an electric mixer until creamy. Gradually add sugar, beating well. Add egg yolks and almond extract, beating until blended.
Combine flour, salt, and cinnamon. Add flour mixture to butter mixture, blending at low speed. Cover and chill dough 1 hour.
Shape dough into 1" balls. Lightly beat egg whites. Dip each ball in egg white; roll in pecans. Place 2" apart on ungreased cookie sheets. Press thumb in each cookie to make an indentation.
Bake at 350° for 15 minutes. Cool 1 minute on cookie sheets; remove to wire racks to cool completely. Press centers again with thumb while cookies are still warm; fill center of each cookie with jelly.