Chess Pie

3 eggs
1 1/2 c. sugar
1/2 c. butter or margarine
1 T. vinegar
1 T. vanilla
1 T. flour
1 unbaked pie crust

Cream butter and sugar together, add flour, vinegar and vanilla. Blend well. Add eggs, one at a time. Mix well. Pour into unbaked pie crust. Bake at 300 degrees for 45 minutes or until mixture comes clean with a knife blade.