Ingredients

2. 3 cups sifted all-purpose flour, plus more for dusting
3. 1 cup unsifted cake flour
4. 1 tablespoon baking powder
5. 1 1/2 teaspoons salt
6. 1 teaspoon baking soda
7. 1 teaspoon cinnamon
8. 1 teaspoon freshly grated nutmeg
9. 3/4 cup sugar
10. 3 extra-large eggs, at room temperature
11. 1 1/2 teaspoons pure vanilla extract
12. 1 cup sour cream, at room temperature
13. 1/4 cup plus 1 tablespoon solid vegetable shortening, melted
14. 1/4 cup milk
15. Vegetable oil, for deep frying
16. Dark Chocolate Glaze or Vanilla Glaze
17. Chopped nuts, toasted coconut and sprinkles, for decorating (optional) 

Directions

1. In a bowl, whisk both flours with the baking powder, salt, baking soda, cinnamon and nutmeg. In a large bowl, beat the sugar with the eggs until pale and thick. Beat in the vanilla. 
2. In another large bowl, whisk the sour cream with the shortening and the milk. Beat the sour cream mixture into the eggs in 2 batches, alternating with the dry ingredients. Cover the bowl loosely with plastic wrap and refrigerate until chilled, at least 2 hours or overnight. 
3. In a large, heavy skillet, heat 4 inches of vegetable oil to 370°. Line a rack with several paper towels. 
4. Meanwhile, turn the dough out onto a floured surface. Roll out the dough 1/2 inch thick. Using a 2 1/2-inch doughnut cutter dipped in flour, cut out as many doughnuts as possible. Reroll the scraps once to cut out more doughnuts. 
5. Working in batches, fry the doughnuts over moderate heat until golden brown, turning them once, about 1 minute per side. Check the temperature of the oil to make sure it doesn't get too hot or too cool. Using a slotted spoon, transfer the doughnuts to the paper towel— lined rack to drain. Serve warm or let cool before glazing with the Dark Chocolate Glaze or the Vanilla Glaze and decorating with chopped nuts, toasted coconut and sprinkles.

Make Ahead

The recipe can be prepared through Step 2 and refrigerated overnight. The finished doughnuts can be made up to 4 hours ahead.