Step 1

Preheat the oven to 350 degrees F.  Line an 8x8 baking pan with parchment paper or grease well.  Set aside.

Step 2

In a large microwave-safe bowl, melt the butter and peanut butter together in 30-second intervals in the microwave. Whisk well until fully melted and combined.

Step 3

Whisk in the brown sugar, egg, vanilla, baking powder, and salt until combined.

Step 4

Add flour and stir with a rubber spatula until a cohesive peanut butter dough is formed.

Step 5

Press the mixture evenly into the pan to form one layer.  Dollop small spoonfuls of the jam on top, then swirl gently with a butter knife. The jam may be a bit hard to swirl and that's ok; it doesn't have to be perfect.

Step 6

Bake for 22-24 minutes, until the edges are lightly browned and the bars look slightly puffed.  Cool completely before cutting into bars!