Chef John s Buttermilk Biscuits

2 cups all-purpose flour

2 teaspoons baking powder

1 teaspoon salt

¼ teaspoon baking soda

7 tablespoons unsalted butter, chilled in freezer and cut into thin slices

¾ cup cold buttermilk

2 tablespoons buttermilk for brushing

Preheat oven to 425 degrees F (220 degrees C).

Line a baking sheet with a silicone baking mat or parchment paper.

Whisk flour, baking powder, salt, and baking soda together in a large bowl.

Cut butter into flour mixture with a pastry blender until the mixture resembles coarse crumbs, about 5 minutes.

Make a well in the center of butter and flour mixture. Pour in 3/4 cup buttermilk; stir until just combined.

Turn dough onto a floured work surface, pat together into a rectangle.

Fold the rectangle in thirds. Turn dough a half turn, gather any crumbs, and flatten back into a rectangle. Repeat twice more, folding and pressing dough a total of three times.

Roll dough on a floured surface to about 1/2 inch thick.

Cut out 12 biscuits using a 2 1/2-inch round biscuit cutter.

Transfer biscuits to the prepared baking sheet. Press an indent into the top of each biscuit with your thumb.

Brush the tops of biscuits with 2 tablespoons buttermilk.

Bake in the preheated oven until browned, about 15 minutes.