In a saucepan over medium heat, melt your butter. Once melted, the butter will begin to foam. Continue stirring (don’t stop!) for 5-8 minutes. After this time, you’ll notice two things: browned specks at the bottom of your pan, and a nutty aroma that will fill the air. Remove from heat, transfer to a glass container and cool for 20 minutes before using.
In a medium sized bowl, whisk together the cooled brown butter and brown sugar. Add in egg and vanilla and continue whisking.
1/2 cup butter, 1/2 cup brown sugar, 1 egg, 1 tbsp vanilla
Add the flour, oats, baking soda, and salt into the bowl. Using a spatula, gently fold in the ingredients until a soft dough forms.
3/4 cups all-purpose flour, 3/4 cups quick oats, 1/2 tsp baking soda, 1/4 tsp salt
Add in the chopped chocolate and fold a few more times.
1/2 cup chocolate chunks
Roll the dough into balls and place 2 inches apart on the prepared baking tray. Gently flatten the dough down. Bake at 350°F for 10 minutes. The cookies will look set around the edges and soft inside.
Let the cookies cool on the baking tray. They will continue to bake as it sits on the warm baking tray. Sprinkle with flaky salt (if desired). Eat warm or let cool and store in an airtight container for up to 5 days.