Preheat oven to 350°F (175°C). Grease a 9″ x 13″ x 2" baking pan. Line the bottom of the pan with parchment paper.
Whisk together the flour, salt, and baking powder. Set aside.
Using an electric mixer on medium speed, beat the butter and sugar together until fluffy (about 2 minutes). Add the eggs, peanut butter, and vanilla, and beat about 2 minutes or until combined.
Add the flour mixture to the butter mixture, and beat on low speed just until combined.
Transfer two-thirds of the dough to the prepared pan and spread evenly. Spread the jam evenly on top of the dough. Crumble the remaining dough on top of the jam. Sprinkle with peanuts.
Bake for 45 to 50 minutes, or until golden. (Tent loosely with foil if the bars are getting too dark.)
Cool the bars to room temperature in the pan on a wire rack. Run a knife around the edges to loosen. Refrigerate 1-2 hours before cutting into bars.