Preheat oven to 350F. Line a 12-count muffin pan with paper liners or spray well with non-stick cooking spray. Set aside
To prepare streusel topping, in a medium bowl, add brown sugar, white sugar, cinnamon, melted butter, and flour. Stir to thoroughly combine. Set aside.
In a large bowl, beat eggs, melted peanut butter, milk, melted butter, brown sugar, and vanilla with a hand mixer or stand mixer with fitted paddle attachment until creamy, about 2 minutes. Set aside.
In another medium bowl, whisk together flour, baking soda, salt, cinnamon, and nutmeg. Gradually add flour mixture to peanut butter mixture, beating until just combined.
Spoon batter into prepared muffin cups, filling about 3/4 full. Spoon about 1 tablespoon of jam or jelly into the center of batter in each muffin cup. Sprinkle prepared streusel evenly over each muffin.
Bake for 20-24 minutes, or until a toothpick inserted into center of muffin comes out clean. Let cool in pan for 5 minutes. Remove from pan and let cool completely on a wire rack. Muffins will keep in an airtight container for up to 5 days.