5 cups unbleached all-purpose flour, sifted before measuring
1 tablespoon plus 1 teaspoon baking powder
2 1/2 teaspoons kosher salt
1 teaspoon granulated sugar
1/8 teaspoon cayenne pepper
4 ounces shredded extra-sharp white cheddar cheese, room temperature (about 1 cup)
4 ounces shredded sharp orange cheddar cheese, room temperature (about 1 cup)
6 tablespoons cold unsalted butter, cut in 1/2-inch pieces
2 cups heavy cream
1/4 cup buttermilk

Homemade Baking Powder

1/4 cup cream of tartar
2 tablespoons baking soda