1 cup (226 g) butter
1 1/2 cups (320 g) brown sugar (packed)
1 large egg + 1 egg yolk
1 tablespoon vanilla extract
3 cups (360 g) all-purpose flour¹
1 teaspoon baking soda
3/4 teaspoon kosher salt (or scant 1/2 tsp. table salt)
10 ounce package chocolate chips
Preheat oven to 375 F. Line baking sheets with parchment paper or silicone baking mat.
Melt butter in a heavy saucepan.
Add brown sugar to a large bowl.
Pour melted butter over sugar.
Stir to combine butter and sugar. Let stand 5 minutes.
Add egg and egg yolk; stir to combine.
Stir in vanilla extract.
Add flour, baking soda, and salt. Stir until just combined. Please see the comments about flour in the recipe notes.
Stir in chocolate chips.
Using a medium cookie scoop (1.5 tablespoon), drop scoops of dough 2 inches apart on prepared cookie sheet.
Bake for about 7-10 minutes, or until the edges of the cookies are golden brown.
Let cool on cookie sheet for 5 minutes. Remove to wire rack to finish cooling.