Preheat oven to 400ºF and spray a muffin pan with nonstick cooking spray. In a medium bowl, whisk the flour, baking powder, baking soda, and salt together; set aside.

In a stand-mixer fitted with a paddle attachment, cream the butter and both sugars together on medium-high until light and fluffy--about 3 minutes. Add eggs, one at a time, mixing well after each addition. Add vanilla.

Mix in a third of the flour mixture, followed by a third of the sour cream. Continue to alternate between the dry mixture and sour cream, until everything has been incorporated. Batter will be VERY thick.

Scoop about 2 Tablespoons of the batter into each muffin well, using two forks to spread batter into the bottom and up the sides of the muffin well.

Spoon about 1 Tablespoon of peanut butter into the center of the muffin batter and top with about a teaspoon of the jam. Top with about 1-2 Tablespoons of batter, ensuring the peanut butter and jam are completely covered.

Use a fork to combine the peanut butter, butter, flour, and brown sugar in a medium bowl until moist crumbs form.

Spoon about a tablespoon or two of the streusel on top of each muffin, making sure that all of the batter is covered. Bake for 20 minutes, or until streusel is golden brown and toothpick inserted in the center comes out with few crumbs.***