Position rack in lower third of oven; preheat to 325 degrees F.
Roll dough between sheets of parchment paper into a 12-inch circle. Peel off the top sheet and invert the dough into a 9-inch pie pan. Press the dough into the bottom and up the sides of the pan. Remove the paper. Fold under the excess dough and flute, or trim with scissors and crimp (see Tip). Refrigerate the crust while you prepare the filling.
Whisk eggs, granulated sugar, butter and flour in a large bowl until well combined. Whisk in buttermilk, orange zest, vanilla, nutmeg and salt. Pour the filling into the prepared crust. Sprinkle cranberries evenly over the top.
Bake the pie until set in the center, 50 to 60 minutes. Cool completely on a wire rack, about 2 hours. Dust with confectioners’ sugar just before serving.
Give your pie a pretty rim! Use scissors to trim the edge of the crust. Press it with a fork to crimp or, for a fancy pattern, press the flat side of the wheel of a scallop-edged pastry cutter into the dough to form little half moons.
9-inch pie pan (not deep-dish), parchment paper
Master Pie Dough