Preheat oven to 350.
Cream together butter, peanut butter, and sugars until completely mixed and creamy.
Add eggs and mixed until combined.
Add baking powder, salt, and flour. Stir together until just combined.
Pour mixture into a greased 9X13 baking dish.
Spoon jelly on top of batter, making sure to evenly spread it across the pan.
In a small mixing bowl prepare the streusel. Mix together flour, brown sugar, cinnamon, salt, oats and butter until clumps begin to form. Sprinkle over the peanut butter batter.
Bake for 40-50 minutes or until a cake tester comes out clean. Let cool completely in pan, then slice and serve. Enjoy!