- 1 cup old fashioned oats (regular or quick)
- 1 cup sugar
- 1 tbsp flour
- ½ tsp salt
- ¼ tsp baking powder
- ½ cup melted butter
- 1 egg yolk, beaten

Mix butter and egg yolk together and set aside.
Mix dry ingredients together. Combine the 2 mixtures and stir with a fork. Refrigerate overnight. Cover cookie sheet with aluminum foil, dull side up. Drop cookie dough by the spoonful on the cookie sheet. Bake at 350 degrees for 12 minutes or until bubbling stops. Remove from oven and let stand 2 minutes. Slide foil onto cool surface for a few minutes. Peel cookies from foil.