Step 1

Preheat the oven to 425 degrees.

Step 2

Line a sheet pan with parchment paper.

Step 3

Place the flour, baking powder,

Step 4

and 2 teaspoons kosher salt in the bowl of an electric mixer fitted with the

Step 5

paddle attachment. With the mixer on low, add the butter and mix only until

Step 6

combined.

Step 7

Combine all the buttermilk and

Step 8

one egg in a small measuring cup and beat lightly with a fork. With the mixer

Step 9

on low, quickly add the buttermilk mixture to the flour mixture and mix just

Step 10

until all of the dough is moistened.

Step 11

Dump the dough onto a

Step 12

well-floured board and knead quickly about 6 times. Roll the dough out ¾-inch

Step 13

thick. Cut with a 2½-inch round (not fluted) cutter and place on the prepared

Step 14

sheet pan. (You can reroll the scraps to make one or two more biscuits.) Brush

Step 15

the tops with egg wash, sprinkle with flaked salt, and bake for 20 to 22

Step 16

minutes, until the tops are browned and the biscuits are cooked through. Serve

Step 17

hot or warm.

Step 18

Note: Grate very cold butter with a

Step 19

box grater (as you would carrots) onto parchment paper to move it easily. Dice

Step 20

any leftover pieces and add them to the dough.