Buttermilk Pie

c butter, softened
2 c sugar
3 Tbs. all-purpose flour
3 eggs
1 c buttermilk
1 tsp. vanilla extract
2 unbaked pastry shell

Cream butter at high speed of electric mixer; gradually add sugar, beating well. Add flour, and beat until smooth. Add eggs; beat until blended. Add buttermilk and vanilla; beat well. Pour filling into pastry shell. Bake at 400 degrees for 5 minutes; reduce heat to 350 degrees and bake an additional 45 minutes or until set. Cool to room temperature; then chill.