In a large bowl, mix muffin mix (without topping), 1 cup milk, 2 eggs, and butter until well-blended. Pour mixture in a greased 8x8" glass dish.
Mix cream cheese, 1/4 cup milk, and 3/4 of the pouch of cinnamon topping together until smooth. Spoon mixture into cake mix and gently fold in. The two should not be mixed, just swirled together.
Spoon pie filling over the cake batter mixture. Again, gently fold in until there are swirls of pie filling incorporated into the cake.
Bake cake at 350 degrees for 40-45 minutes, until cake is not jiggly in the middle. The swirls might still be jiggly, but cake part should not move and should be firm to the touch on top.
While cake is baking, mix together 1 cup of powdered sugar and a splash of milk. In separate bowls, divide granulated sugar into 3 parts and, with 5-6 drops of food coloring each, color the sugar.
Once cake is finished baking and cooled for 10-15 minutes, pour powdered sugar mixture over the top. Sprinkle dyed granulated sugar over icing.