Preheat your oven to 350°F (175°C). Line a 9×13-inch baking dish with parchment paper, allowing some overhang on the sides for easy removal later.
In a large mixing bowl, cream together softened butter, creamy peanut butter, and sugar until the mixture is light and fluffy, which should take about 3-4 minutes.
Add in two large eggs one at a time, ensuring each is well mixed before adding the next egg. Stir in one teaspoon of pure vanilla extract for added flavor.
In a separate bowl, whisk together three cups of flour and one teaspoon of baking powder until evenly combined. Gradually mix this dry mixture into your wet ingredients until a dough forms.
Press about two-thirds of the dough evenly into the prepared baking dish to form a solid base layer that will hold the juicy strawberry jam in place.
Spread two cups of strawberry jam evenly over your base layer, leaving some space around the edges. Crumble the remaining dough over the jam layer for an appealing texture before baking.