Cream butter and sugar together until light and fluffy. Add one egg yolk at a time, beating well after each one. Add 1/2 cup milk alternately with flour, ending with flour. Add vanilla and lemon flavorings.
Preheat oven to 350º. Pour into an unbaked pie shell and bake until the middle is set.
Make a meringue by beating egg whites until peaks form. Gradually add 1/4 cup sugar and beat until stiff peaks form. Spread over pie and place in hot oven. Turn off oven and brown for about five minutes.