Buckwheat Chocolate Chip Cookies

INGREDIENTS

Egg, large

Egg yolk, large

1 cup

All-purpose flour

1/2 tsp

Baking soda

1/2 cup

Brown sugar, packed light

1/4 cup

Buckwheat flour, whole-grain

3 tbsp

Buckwheat groats or cocoa nibs, roasted

1/3 cup

Granulated sugar

1/2 tsp

Kosher or sea salt

Sea salt, flaky

1 1/2 cups

Semisweet or bittersweet chocolate

1/2

Teaspsoon baking powder

1 1/2 tsp

Vanilla extract

3/4 cup

Walnuts

8 tbsp

Butter, salted or unsalted