Combine the dry ingredients in a bowl. Cut the butter into the flour mix. Mix in the egg and the buttermilk. Knead the dough until smooth, shape into a disc, wrap, and refrigerate for 1-24 hours.
Spray a 9 inch pie pan. Roll the dough into a 1/4 inch thick circle. Line the pan with the crust. Crimp the edges of the crust and refrigerate while making the filling.
Filling
Preheat the oven to 350 degrees. Line the bottom of the crust with cherry halves. Combine the dry ingredients in a bowl. Mix in the eggs, buttermilk, vanilla, butter, and orange juice.
Pour the filling into the prepared crust and bake for 30 minutes. Rotate the pie and bake for another 20-30 minutes or until custard has set. Cool to room temperature and refrigerate.