INGREDIENTS
1 stick
(4 ounces, 113 grams) unsalted butter
3/4 cup
dark brown sugar
1
large egg plus 1 egg yolk
1 tsp
vanilla extract
1/4 tsp
fine salt
1 cup
(4.5 ounces, 128 grams) all-purpose flour
1/3 cup
milk chocolate chips, plus more for sprinkling
1/3 cup
white chocolate chips, plus more for sprinkling
1/3 cup
semisweet chocolate chips, plus more for sprinkling