Position a rafk in center of oven & preheat to 350°F. Line an 8" square baking pan with an 8X13 sheet of parchment paper, excess hanging over.

Using a food processor, pulse the peanuts until chopped. Transfer to a medium bowl.

In the processor bowl (no need to clean), mix the 2 flours, brown sugar and salt. Add the butter; pulse umtil the mixture resembles coarse meal. Add the peanut butter and vanilla; process umtil crumbly. Measure out 2/3 cup of the crumb mixture; transfer to the bowl of peanuts.

Dump tje remaining crumb mixture into the prepared pan and pat down firmly (it doesnt have to be perfectly even.). Spoon the jam on top and spread to within 1/2 inch of the edges. Sprinkle the peanut-crumb mixture evenly over the top, going all the way to the edges of the pan.

Bake until golden brown and the jam is bubbling, about 45 minutes. (If browning too quickly on top, lay a sheet of foil loosely over pan.) Transfer pan to a rack to cool completely.

Grasp the parchment paper and gently lift entire dessert out of pan. Cut into 16 squares.