Peanut Butter Cookie Bars

Instructions

1. Preheat oven to 350°F and line a 9×13-inch pan with parchment paper (or lightly grease and flour the pan).
2. In a large bowl, cream together butter, peanut butter, and sugars with a hand mixer until fluffy.
3. Mix in the egg, yolk, and vanilla extract.
4. In a medium bowl, whisk together flour, cornstarch, baking powder, and salt until well combined.
5. Gradually add the dry mixture to the wet mixture until it is completely combined.
6. Add milk and stir again until mixture is well incorporated.
7. Fold in chocolate chips.
8. Transfer batter to prepared pan and use a spatula to spread it evenly into pan.
9. Bake for 35-40 minutes or until edges are just beginning to turn golden brown and a toothpick inserted in the center comes out clean or with a few moist crumbs.
10. Allow to cool completely before cutting and serving.