In a skillet over medium heat, combine the topping ingredients until the butter and sugar substitute melt together. Spread this mixture on parchment paper and let it cool.
In a mixing bowl, combine the muffin ingredients and blend until smooth.
Line a muffin tin with cupcake liners and fill each liner about ¾ full with the batter.
Use a spoon to create a hollow in the center of each muffin.
In another bowl, mix the filling ingredients until smooth, then transfer to a ziploc bag and snip off a corner. Pipe the filling into each muffin's center and top with the crumbled mixture.
Bake for 20 minutes or until fully cooked.
Notes
Enjoy these delightful muffins as a low-carb treat!