Do not preheat your oven.
By hand or with a mixer, cream together sugar, peanut butter, and butter. Stir in the egg and vanilla.
In a separate bowl or large plastic ziploc bag, mix together the flour, baking powder, and salt.
Add the dry ingredients to the wet ingredients slowly, mixing thoroughly, until a thick dough forms.
Press 3/4 of the peanut butter dough into the bottom of a parchment paper-lined 9x13 baking dish. Place the dish in the fridge to chill for at least one hour, but no more than 1 day, allowing the butter to re-solidify. Place the other 1/4 of peanut butter dough in the freezer until ready to use, this will make it easier to crumble over the top of the bars before baking.
When ready to bake, heat the strawberry jam in the microwave for 30 seconds, or until the jam is slightly more liquid. Spread it evenly over the peanut butter dough in the pan.
Remove the rest of the peanut butter dough from the freezer and crumble it over the jam-covered dough in the pan.
Bake in a non-preheated oven at 350°F for approximately 20 minutes, or until the top crust is golden brown and the jam is bubbly.
Allow the bars to cool before attempting to slice, or you may have a sticky yet delicious mess on your hands.
Source:
spendwithpennies.com