Preheat oven to 350 degrees.
Grease 13x9 inch baking pan.
Mix together butter and sugar until light and fluffy and well combined
Add eggs, vanilla extract, and peanut butter and mix until it is all combined
Add flour and baking powder to the mixture.
Mix until well combined.
Spread 2/3 of the batter mixture onto the bottom of the pan.
Spread jam on top of the batter.
Crumble the remaining dough over the jam in small bits making sure to fully cover the jam
Bake for about 25-30 minutes
Remove from oven and let cool for 30 minutes before slicing