Salted Shortbread Chocolate Chunk Cookies

INGREDIENTS

1 cup

plus 2 tablespoons (2 1/4 sticks) cold salted butter, cut into 1/2-inch pieces

1/2 cup

granulated sugar

1/4 cup

packed light brown sugar

1 tsp

vanilla extract

2 1/4 cups

all-purpose flour

6 oz

dark chocolate (chopped (you want chunks))

large egg, (beaten)

Sparkling sugar, (for rolling)

Flaky sea salt, (for topping (like Maldon's sea salt))