Preheat oven to 350ºF and line an 8" square pan with foil, leaving a foil overhang on opposite sides of the pan. Grease foil with nonstick cooking spray.
In a large bowl, whisk together 4 1/4 ounces (1 cup, spoon and level) all-purpose flour with the whole wheat flour, baking powder and salt.
In the bowl of a stand mixer (or using a handheld electric mixer), cream together 2 ounces (4 tablespoons) butter and brown sugar. Wiping down the bowl and beater as needed, beat in the eggs one at a time, until well-combined. Add the peanut butter and vanilla extract and beat in until evenly incorporated.
Add the dry ingredients to the wet and mix in at lowest speed until just combined. Set aside 7 ounces (3/4 cup) batter. Press remaining batter into the bottom of the prepared pan, using your hands to spread the dough across the entire surface of the pan in an even layer. Lay a sheet of parchment over the dough and use your hands to smooth and flatten out the surface of the dough. Pour jelly on top and spread evenly over the surface (or just tilt the pan around to spread it out in an even layer). Bake in preheated oven for 15 minutes.
Meanwhile, add the remaining 2 1/8 ounces (1/2 cup, spoon and level) all-purpose flour and 1/2 ounce (1 tablespoon) butter to the reserved cookie batter, rubbing in with your hands until the butter and flour have disappeared into the mixture and the entire mixture is crumbly, with no large pieces of dough remaining. Place in the freezer while bars are baking.
Once the first 15 minutes of baking are done, sprinkle the crumble mixture evenly over the bars. It will look like a lot, but be sure to use it all. Bake for another 15 minutes. The crumble topping should just barely be starting to crisp up and turn slightly golden. Cool bars completely, and then use foil to lift from the pan and slice. Store in an airtight container.