Preheat oven to 375.
Cream together butter, 2 cups of sugar, one whole egg, and one egg white (save the yolk for a later step).
Mix together baking soda, flour, and dash of cinnamon. Add to wet ingredients.
Refrigerate for 2-3 hours.
When the dough is almost finished chilling, beat remaining egg yolk. Set aside.
Mix together 2 tbsp cinnamon and ½ cup of sugar. Set aside.
Once chilled, roll out the dough as thin as possible on wax paper or pastry cloth and cut out 3-4" circles using a cookie cutter or cup.
Spray cookie sheet with oil and place cookies on sheet.
Using the back of a teaspoon dab it in the egg yolk then dab into the center of the cookie.
Sprinkle the cinnamon sugar mixture on top.
Bake for 8-10 minutes.