French Coconut Pie

This is my Mama's recipe and she was the BEST cook.

1 1/4 cup sugar
6 tablespoons butter
1/4 cup buttermilk
3 eggs
1 3/4 cup angel flake coconut
1 teaspoon vanilla
1 unbaked frozen shell

Cream sugar and butter together.  Add Buttermilk.  Beat eggs slightly and add.  Stir in vanilla. Add coconut and then pour into unbaked pie shell.  Bake at 375 degrees for 10 minutes then lower the heat to 300 and cook until golden brown and firm to touch in the center.  About 35-40 minutes.