In a skillet over medium heat melt the butter. Once the butter is melted, it will begin to sputter and foam. Stir occasionally for 5-10 minutes until it gets brown and smells nutty. Keep a close eye on it to make sure it doesn't burn. Remove from the heat and cool completely.
1 cup unsalted butter
Preheat oven to 350º F.
Once the butter has cooled completely add it to a bowl of an electric mixer. Cream the sugar, brown sugar, and butter together.
1 cup unsalted butter, 1 cup light brown sugar, 1/3 cup granulated sugar
Mix in the egg, egg yolk, milk and vanilla until well blended.
1 whole large egg, 1 large egg yolk, 2 Tablespoons milk, 2 teaspoons vanilla extract
Add flour, baking soda, and salt. Mix until well combined.
2 1/4 cup all-purpose flour, 1 teaspoon baking soda, 1 teaspoon salt
Using a spatula fold in chocolate chips, and toffee chips.
12 oz semi-sweet chocolate chips, 10 oz Heath Toffee Bits
Scoop small balls of dough onto a cookie sheet. I like to chill the dough for 30 minutes here to make sure the butter has firmed up enough, but this is optional.
Bake for 11-12 minutes, or until just golden along the edges and the tops appear completely set and dry. Be careful not to over bake.
Remove from oven, and allow to cool for a few minutes before removing to a wire rack.
Notes
You can use softened butter in this recipe if you do not want to make browned butter.Adapted from From Cupcakes to Caviar