Preheat oven to 350 F. Grease standard 12-cup muffin tin or line with paper liners*.
Melt butter in a heavy saucepan.
1 cup (226 g) butter
Add brown sugar to a large bowl.
1 ½ cups (320 g) brown sugar
Pour melted butter over sugar.
Stir to combine butter and sugar. Let stand 5 minutes.
Add egg and egg yolk; stir to combine.
1 large egg, 1 egg yolk
Stir in vanilla extract.
1 tablespoon vanilla extract
Add flour, baking soda, and salt. Stir until just combined.
3 cups (360 g) all-purpose flour, 1 teaspoon baking soda, ¾ teaspoon kosher salt or scant 1/2 tsp. table salt
Stir in chocolate chips.
10 ounce package chocolate chips
Using a medium cookie scoop (1.5 tablespoon), drop a scoop of cookie dough into each muffin cup.
Bake for about 7-10 minutes, or until the edges of the cookies are just beginning to reach golden brown.
Let cool in muffin tin for 5 minutes. Remove to wire rack to finish cooling.
Video
Notes
*I like to use parchment liners. They have a nonstick coating that makes for easy peeling.**I suggest stirring this recipe together by hand rather than using a hand or stand mixer.***Nutrition facts are estimated.