2sticks (16 tablespoons; 8 ounces) unsalted butter, browned and brought back to room temperature
1cup+ 2 tablespoons dark brown sugar
2large eggs, at room temperature
Preheat oven to 375 degrees (F). Line 2 large baking sheets with parchment paper; set aside.
In a medium-sized bowl whisk together the flour, baking soda, and sea salt; set aside.
Place one stick of butter in a small sauce pan over medium-high heat and cook for about 3 minutes – stirring almost constantly – or until the butter has browned. Remove from heat and stir in remaining stick of butter; whisk until completely smooth. Pour the hot butter into a heat proof bowl, then place the bowl in the refrigerator or freezer and bring the butter back to room temperature. *You’ll know the butter is at room temperature when you press a finger into the top and it makes a slight indentation.
Once the butter is at room temperature…
Add the sugars and the vanilla to the browned butter and beat on medium-speed until light and fluffy; about 2 minutes (you may use a stand mixer/ handheld mixer to help if you have one). Add the eggs and beat quickly – for only about 30 seconds – until they’re just combined; scrape down the sides of the bowl with a rubber spatula. Let the mixture rest for 5 minutes, then beat the eggs for another 30-45 seconds. Gently fold in the flour mixture with a wooden spoon, stirring only until the flour begins to disappear. Fold in the m&m minis.
Roll scant tablespoon sized balls of dough between your palms to form a ball, then place on prepared sheet (make sure to leave a little bit of room in between each cookie for inevitable spreading). Continue this process until all the dough has been rolled. Place baking sheets, one at a time, in preheated oven and bake for 7-8 minutes, or until golden at the edges but still soft in the middle. Let cookies cool for 15 minutes on the sheet before transferring to a wire wrack to cool completely.