In a medium saucepan, melt the butter over medium heat, then bring it to a boil. Once it starts boiling, swirl the pan constantly until the butter passes foamy phase and becomes a deep amber color. Remove from the heat, and transfer to a measuring cup or bowl to cool slightly. Stir in 1 teaspoon water. ¼ cup (½ sticks, 57 g) salted butter 1 teaspoon water
In a second small mixing bowl, whisk together the flour, baking soda, and salt. Set aside. ½ cup + 2 Tablespoon (75 g) all purpose flour ¼ teaspoon baking soda ¼ teaspoon fine sea salt
To the browned butter, add the brown sugar, granulated sugar and whisk to combine. Then add in the egg yolk, vanilla and stir to combine. ¼ cup (53 g) packed light brown sugar 2 Tablespoons (25 g) granulated sugar 1 large egg yolk ½ teaspoons vanilla extract
Add in the dry ingredients. Stir using a wooden spoon or spatula until the dough comes together and the ingredients are evenly incorporated. Stir in the chocolate chips and toffee bits. ⅓ cup (57 g) semi-sweet chocolate chips ¼ cup toffee bits
Scoop dough into 3-Tablespoon portions. Cover and Chill for 1 hour for best results and less spreading and thicker cookies.
Position a rack in the center of the oven and preheat the oven to 350°F(180℃). Line a baking sheet with parchment paper.
Bake for 10 to 12 minutes until the edges are lightly golden and tops are puffy but set. Remove from the oven and use a large round cookie cutter or coffee mug and place over each cookie rotating in a circle to bring the edges in.
Allow the cookies to cool for 5 minutes on the baking sheet, then transfer them to a wire rack to cool completely. If desired sprinkle a small amount of flaked sea salt on top of the cookies as they are cooling. Store airtight at room temperature for up to 3 days.