Preheat the oven to 350 degrees.
Stir together the topping ingredients in a skillet over medium heat until the butter and sugar have melted.
Spread the mixture onto a piece of parchment paper, and allow to cool.
Add the ingredients for the muffins to a mixing bowl, and blend until smooth.
Place cupcake liners in the sections of a muffin tin.
Fill each of 8 cupcake liners ¾ of the way full with the batter.
Use a spoon to hollow out a hole in the center of each muffin.
In a mixing bowl, blend together the filling ingredients until smooth.
Place the filling into a ziploc bag, and cut off the corner.
Pipe the filling into the center of each muffin.
Sprinkle each muffin with the crumbled up topping.
Bake for 20 minutes, or until cooked through.