- 3 teaspoons baking powder
- 2 1/2 teaspoon kosher salt
- 1 teaspoon sugar
- 1/4 teaspoons baking soda
- 5 1/2 cups all-purpose flour, plus more
- 1 1/2 cups (3 sticks) chilled unsalted butter, cut into pieces
- 1 1/2 cups chilled buttermilk
- 1 large egg, beaten to blend
- Preheat oven to 375°F. Pulse baking powder, salt, sugar, baking soda, and 5 1/2 cups flour in a food processor. Add butter and pulse until the texture of coarse meal with a few pea-size pieces of butter remaining.
- Transfer mixture to a large bowl. Mix in buttermilk with a fork, then gently knead just until a shaggy dough comes together.
- Pat out dough on a lightly floured surface until 1 1/4″ thick. Cut out biscuits with a 3″ biscuit cutter, rerolling scraps once.
- Place biscuits on a parchment-lined baking sheet and brush tops with egg. Bake until golden brown, 30–35 minutes.