Brown the Butter: In a medium saucepan, melt 1 cup of unsalted butter over medium heat, watching closely for it to turn golden brown, around 5-7 minutes.

Mix Sugars and Butter: In a large bowl, combine the cooled brown butter with 3/4 cup brown sugar and 1/4 cup granulated sugar. Mix until smooth.

Incorporate Eggs: Add 2 large eggs one at a time, whisking well after each addition. Stir in 1 teaspoon of vanilla extract.

Combine Dry Ingredients: Whisk together 2 cups flour, 1 teaspoon baking soda, and 1/2 teaspoon salt. Gradually mix it into the wet ingredients.

Fold in Add-ins: Gently fold in 1 cup toffee bits and 1/2 cup chocolate chips into the dough.

Chill Dough: Cover the bowl with plastic wrap and refrigerate for at least 30 minutes to 1 hour.

Preheat Oven: Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.

Shape Cookies: Drop rounded mounds of dough onto prepared baking sheets, spacing them about 2 inches apart.

Add Flaky Salt: If desired, sprinkle a pinch of flaky sea salt on each cookie mound before baking.

Bake: Bake the cookies in the oven for 10-12 minutes until edges are lightly golden.

Cool: Let cool on the baking sheets for about 5 minutes before transferring to a wire rack.