Scrape the solidified butter into the standing mixer, and add the brown and cane sugars as well. Gradually increase speed and mix on high for 2-3 minutes until creamy. Scrape down the sides of the bowl halfway through.
1 ¼ cup light brown sugar, ½ cup cane sugar
In a separate bowl, whisk together the flour, sea salt, cornstarch, and baking soda. Set aside.
2 ¾ cup all purpose flour, 1 teaspoon fine sea salt, 2 teaspoon cornstarch, 1 teaspoon baking soda
After creaming the butter and sugar, add eggs and vanilla and mix on medium speed until well combined. Scrape down the sides of the bowl halfway through.
2 large eggs, 1 tablespoon vanilla extract
Add the mixed dry ingredients to the standing mixer and mix on the lowest setting until just combined. While the flour is mixing in, add the toffee bits and chocolate chips. Doing this as the dry ingredients are still mixing in minimizes the risk of overworking the cookie dough.
1 cup Heath English toffee bits*, 1 ½ cup milk chocolate chips (I prefer Ghirardelli)
Roll the dough into 12 balls and press extra toffee and chocolate chips into the top of each. Place them in the refrigerator for an hour to chill the dough. (Or for 15 minutes in the freezer if you are in a hurry.)**