Brown Butter Toffee Cookies

Name: Brown Butter Toffee Cookies
Prep time: 30 min
Cook time: 10 min
Total time: 40 min
Cuisine: American
Ingredients: 1 cup unsalted butter; 1 cup brown sugar ((200g) (light or dark is fine, I like to use a blend of the two)); ⅔ cup white sugar ((135g)); 2 eggs (room temperature preferred); 1 ½ teaspoon vanilla extract; 2 ¾ cups all-purpose flour ((350g)); 1 teaspoon cornstarch (cornflour in UK); 1 teaspoon baking powder; 1 teaspoon baking soda; ¾ teaspoon salt; 1 cup milk chocolate toffee pieces ((Like Heath Milk Chocolate Toffee Pieces) (170g)); sea salt (for sprinkling on top of the cookies (fine or coarse, your preference))