Double-Buckwheat Double-Chocolate Cookies

INGREDIENTS

Egg yolks, large

1/4 cup

kasha

1/2 cup

sugar

1 cup

buckwheat flour

1/4 cup

unsweetened cocoa powder, unsweetened

1 2/3 cups

all-purpose flour

1/4 cup

packed light brown sugar, packed light

8 oz

Bittersweet chocolate

2 tsp

Sanding sugar

1 tsp

Sea salt, fine

1 tsp

Vanilla extract, pure

2 sticks

8 ounces; 226 grams unsalted butter, unsalted