Preheat the oven to 350 degrees f.
Prepare the muffin pans with nonstick cooking spray, or if you prefer, put liners into the muffin cavities.
Place the cake mix, eggs, milk and butter into the mixing bowl and combine thoroughly.
Gently fold in the frozen berries.
Pour the mixture into the muffin cavities, dividing equally.
Bake for 20-25 minutes, until the muffins are turning golden brown.
Let cool for at least 5-10 minutes before serving, depending on how warm you like them.
While the muffins are cooling, melt 1-2 tbsp of butter in the microwave
Brush that butter on top of the muffins, then sprinkle some of the colored sugar on the top.
Serve and enjoy!