1 c. sugar
1 c. butter
2 eggs, beaten
3 tbsp. sour milk (add a tsp. or so vinegar to the milk to sour it)
1 level tsp. baking soda
3 c. flour
1/4 tsp. salt
1 tsp. vanilla

Cream butter and sugar. Add beaten eggs. Mix soda in milk and add vanilla, flour and salt. Knead and roll thinly and bake at 375 degrees for 5 to 10 minutes (just until touched with brown, if let get too brown, will be hard). Keep an eye on them if they're really thin. Cool and frost.