Shortbread Cookies (Jan's Recipe from Great Grammie Keith)

3 3/4 cup flour
1/4 cup corn starch
1 1/4 cup icing sugar
1 pound good butter
1 tsp vanilla

Have butter at room temperature (cream)
Add vanilla
Add dry ingredients until well blended (use hands)
Shape into about 5 or 6 balls
Place in fridge to make firm
Pat dough with hand and roll with rolling pin to 1/4 inch
Shape cookies
Bake 300F for 15 to 25 minutes