2sticks (227 grams) unsalted butter, at room temperature
1cup(269 grams) creamy conventional peanut butter
3/4cup(150 grams) granulated sugar
1 1/4cups(250 grams) lightly packed light brown sugar
2large eggs, at room temperature
1large egg yolk, at room temperature
2cups(180 grams) old-fashioned rolled oats
1 1/2cups(255 grams) semisweet chocolate chips or chunks
Preheat the oven to 350°F. Line large baking sheets with parchment paper.
In a medium bowl whisk together the flour, salt, baking powder, baking soda, and cinnamon.
In a large bowl, use an electric mixer to beat the butter, peanut butter granulated sugar, and brown sugar on medium-high speed until light and fluffy, about 2 to 3 minutes. Beat in the eggs, egg yolk and vanilla, one at a time, beating well after each addition. Slowly beat in the flour mixture until just combined. Add in the oats and chocolate chips until just combined.
Using a spoon or spring-loaded scoop, drop 3-tablespoon sized balls of dough onto prepared baking sheets. Flatten slightly with the bottom of a measuring cup.
Bake for about 12 minutes, or until the edges are slightly browned, rotating baking sheets halfway through. Let the cookies cool on baking sheets for 5 minutes before removing to wire wracks to cool completely. Cookies can be stored in an airtight container at room temperature for up to 3 days.