single-serve brown butter chocolate chip cookie

Preheat the oven to 350 F. Start by browning the butter -- add the butter to a pan over medium heat. Stir the butter as it melts. After a few minutes the butter will start to bubble, then will foam up. Once the foam subsides, you'll be left with brown, nutty smelling butter! Pour into a glass container and transfer to the freezer for 10 minutes.
Once the brown butter has set up a bit, transfer it to a mixing bowl. Add the brown sugar and white sugar and whisk until well combined and smooth.
Crack one egg into a bowl and whisk until the yolk and whites are combined. Add 2 tablespoons of the mixed egg to the sugar mixture (use the rest of the egg for something else -- more cookies or add to an omelet!). Add a splash of vanilla and whisk until the mixture is smooth and combined.
Add the flour, cornstarch, baking soda, and pinch of salt. Use a rubber spatula to mix until the dough is just combined.
Add the chocolate chips or chunks and mix into the dough. Use a 4oz cookie scoop and scoop two large cookies onto a lined baking sheet. If you want, press a few extra pieces of chocolate gently on top of the cookies.
Bake for 8-10 minutes, until the cookies are just starting to brown on the edges. Remove from the oven and let them cool completely. Top with some flakey salt (optional) and enjoy!