Peanut Butter Chocolate Chip Bars

I needed to make a cookie bar that everyone would love and so I pulled this cookbook from the shelf- All-Butter, Fresh Cream, Sugar-Packed, No-Holds-Barred Baking Book by Judy Rosenberg, owner of Rosie's Backery. Sure it was printed in 1991, but that doesn't mean the recipes are outdated!
I chose this recipe because everyone loves peanut butter and chocolate and subbed in some m&m baking bits, just for fun.

Peanut Butter Chocolate Chip Bars
1 1/3 cups + 1 Tbls + 1 tsp all-purpose flour
2 tsps baking powder
1/8 tsp baking soda
1/4 tsp salt
8 Tbls (1 stick) unsalted butter, at room temperature
1/2 cup creamy peanut butter
1/2 cup + 2 Tbls packed light brown sugar
1/2 cup granulated sugar
1 tsp vanilla extract
2 large eggs, at room temperature
1 cup semi-sweet chocolate chips (I used 1/2 cup milk choco chips and 1/2 cup m&m baking bits)

Preheat the oven to 350 degrees F. Lightly grease a 11 by 7 inch baking pan with butter or cooking spray. Whisk together the flour, baking powder and soda, and salt together in a mixing bowl and set aside.

Using an electric mixer on medium-high speed, cream the butter, peanut butter, sugars, and vanilla, until light and fluffy, about 1 1/2 minutes. Stop the mixer to scrape down the sides with a rubber spatula.

Add the eggs one at a time, and beat on medium speed until partially blended after each addition, about 1 1/2 minutes. After the last addition, beat until blended, about 30 seconds, stopping the mixer twice to scrape down the sides.

Add the dry ingredients to the batter and mix with a spatula until the flour is absorbed. Then mix on low speed, until blended, 7 to 10 seconds. Scrape the bowl, especially the bottom.

Add the chocolate chips and blend for several seconds. Scrape the bowl. Spread the batter evenly in the prepared pan.

Bake the bars on the center oven rack until the edges are deep golden and the center in lightly golden and slightly puffy, 25 to 30 minutes. The center will drop when the bars are taken out of the oven, creating a chewy texture. Cut the bars into squares after they have cooled a bit on the rack.