Buttermilk Pie

Ingredients:
1 1/4 cups low fat buttermilk
2 large eggs, separated
1 disk refrigerated pie dough
1 stick unsalted butter
1 1/4 cups granulated sugar
3 Tbsps all-purpose flour
1 Tbsp fresh lemon juice
1/2 tsp finely grated lemon zest
1/4 tsp nutmeg
1/4 tsp salt
Confectioners sugar for dusting

Let buttermilk & eggs come to room temperature 1 hr before making filling
Preheat oven to 350
Ease dough into 9" deep-dish pie plate & crimp as desired
Pierce all over with a fork
Line dough with foil, then fill with pie weights or dried beans
Bake until edges are golden, about 20 mins
Remove the foil & weights & continue baking until lightly golden all over, about 10 more mins
Let cool completely on wire rack
Make the filling: beat the butter & sugar in a stand mixer fitted with the wish attachment on medium-high speed until combined, about 1 min
Add the egg yolks & beat until pale & thick, about 1 min
Reduce mixer speed to medium-low; add flour, lemnon juice, lemon zest, nutmeg & salt & beat until just incorporated
Increase the mixer speed to medium-high & slowly pour in buttermilk
Scrape down the sides of the bowl & continue beating until combined
Transfer to a large bowl
Clean the mixer & whisk attachment
Add the egg whites & beat on medium-high speed until stiff peaks form, about 4 mins
Fold the egg whites into the yolk mixture in 3 additions until no white streaks remain
Pour the filling into the prepared crust
Transfer to a baking sheet & bake until golden & set around the edges (the center will still jiggle), 45-50 mins, rotating the pie halfway through
Let cool on rack
Dust with confectioners sugar before serving