Preheat the oven to 350 degrees F. Spray a 9x13-inch baking pan with cooking spray. Line it with parchment paper and spray it again. Set aside.
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer, cream the butter and sugar together for about 2 minutes, or until it is light and fluffy. Add the vanilla extract, followed by one egg at a time. Then add the peanut butter and mix until everything is smooth and incorporated. Scrape down the sides of the bowl as needed.
Spread 2/3 of the dough in the bottom of the prepared pan in an even layer. Spread the jam evenly on top of the dough. Drop small blobs of the remaining dough on top of the jam. Sprinkle the peanuts on top.
Bake for 45 minutes, or until golden brown. Allow the bars to cool completely before slicing.