Buttermilk pie is one of my favorites also. Here's another recipe, I haven't tried yet, that sounds good. Very unusual crust.
Buttermilk Pie in Cornmeal Pastry
Unbaked Cornmeal Pie Shell
3 eggs, separated
1 cup sugar
1 Tbls. butter
1/4 cup flour
2 cups buttermilk
l/4 tsp. grated lemon peel
2 Tbls. lemon juice
Meringue (3 egg whites)
Beat yolks, adding sugar gradually. Cut butter into flour; add
buttermilk, lemon peel and juice. Fold in yolks. Pour into 9"
Cornmeal Pie Shell. Bake in hot oven (425F.) 10 minutes; reduce
temperature to 350F. and bake 20 to 25 minutes. Cool. Pile meringue
lightly over cooled filling. Bake in moderate oven (350F.) 12 to
15 minutes.
CORNMEAL PIE SHELL: Sift together 1 c. sifted flour and 1/2 tsp.
salt; stir in 1/2 c. cornmeal. Cut in 1/2 c. shortening until
mixture resembles fine crumbs. Stir in 1/2 c. grated Cheddar cheese;
sprinkle 1/4 c. water over mixture gradually, mixing lightly with
fork. Shape into ball; flatten on lightly floured surface. Roll to
about 1/8" thickness. Line 9" pie pan; trim and flute edge. Fill
and bake as directed.