1/2 c. butter, soft
1/4 c. sugar
1 egg yolk
1 tsp. vanilla
1 c. flour
2 tbsp. cornstarch
1/2 tsp. salt
3/4 tsp. baking powder

Cream butter and sugar together well. Add egg yolk and vanilla. Sift together dry ingredients. Work dry ingredients into butter mixture with a fork. Shape into small balls and roll in oatmeal. Place on ungreased cookie sheet. Bake at 375 degrees approximately 10-12 minutes.