In a large bowl, use an electric mixer to combine the butter and sugar, beating well. Add the egg yolks and almond extract, beating until blended.
In a separate bowl, whisk together the flour, salt and cinnamon. Add the flour mixture to the butter mixture, blending at low speed. Cover and chill the dough for 1 hour.
Preheat the oven to 350°F.
Shape the dough into 1-inch balls. Lightly beat the egg whites with a fork. Dip each ball in egg white; roll in pecans. Place 2 inches apart on ungreased baking sheets. Press your thumb in each cookie to make an indentation.
Bake for 15 minutes. Cool 1 minute on baking 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.