In a large bowl, combine the flour, brown sugar, baking powder and salt.
In another bowl, use a whisk to mix the egg, milk, peanut butter, oil and vanilla until well combined.
Add the dry ingredients into the peanut butter mixture and stir just until combined.
Line a muffin tray with 12 paper baking cups. Fill each cup about halfway with batter.
Use a tablespoon sized cookie scoop to place one tablespoon of jelly on top of the batter. Place an additional tablespoon of peanut butter batter on top of the jam and spread to cover the jelly.
Bake at 350° F for 30 minutes. Cool for 5 minutes before removing muffins from pans to wire racks.