Peanut Butter Chocolate Chip Cookie Bars

INGREDIENTS

1 cup

unsalted butter, softened to room temperature

1 cup

creamy peanut butter

1 1/2 cups

light brown sugar, tightly packed

1/2 cup

sugar

large egg + 1 large egg yolk

2 tsp

vanilla extract

2 3/4 cups

all-purpose flour

1 tsp

cornstarch

1/2 tsp

baking powder

1/4 tsp

salt

2 tbsp

milk

2 cups

chocolate chips (semisweet or milk chocolate would work great)