1 ½sticks (170 grams) unsalted butter, at cool room temperature
1 ¼cups(250 grams) packed dark brown sugar
¾cup(150 grams) granulated sugar
2large eggs plus one egg yolk,at cool room temperature
1teaspoonvanilla extract
3cups(297 grams) old-fashioned rolled oats
1 ½cups(255 grams) semisweet chocolate chips
Instructions
Preheat oven to 350°F and line large baking sheets with parchment paper.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon. Set aside.
In a large bowl, use a stand mixer to beat the butter, brown sugar, and granulated sugar on medium-high speed until smooth and well combined (about 1 to 2 minutes).
Beat in the eggs and vanilla, and then, on low speed, gradually add the flour mixture and beat until just combined.
Stir in the oats and chocolate chips.
Using a large spring-loaded cookie scoop, drop 3-tablespoon-sized balls of dough onto prepared cookie sheets and flatten slightly with the bottom of a measuring cup.
Bake for 14 to 15 minutes, or until the edges are slightly browned, rotating cookie sheets halfway through. If you prefer a slightly softer cookie, bake for about 12-13 minutes, or until the edges are slightly brown but the middle still looks underdone (it will firm up while cooling).
Let the cookies cool on baking sheets for 5 minutes before removing to wire racks to cool completely.
Video
Notes
For softer, chewier cookies, pull them from the oven when the edges just start to brown but the centers still look glossy. They’ll finish cooking from residual heat. That carryover baking gives the cookie a perfectly chewy texture.