The Kitchn: Old-fashioned buttermilk bar donuts are crispy, fluffy perfection
For the donuts:
4 tablespoons (1/4 cup) unsalted butter
3 1/2 cups cake flour, plus more for dusting
2 3/4 teaspoons baking powder
1/4 teaspoon baking soda
1 1/2 teaspoons kosher salt
3/4 teaspoon ground nutmeg
1/2 cup packed light brown sugar
1/2 cup granulated sugar
1 tablespoon vanilla extract
...continued