Preheat your oven to 350 degrees F.
Line your muffin tin with cupcake liners. In a small bowl, melt butter in the microwave. In a separate bowl, mix together cinnamon and sugar.
Using a pair of clean kitchen scissors, cut each biscuit into 4-5 smaller pieces. You will have about 32-40 dough pieces total when you are finished.
Dip each piece of dough in butter; making sure to cover the entire surface. Then roll the buttered dough around in the cinnamon and sugar mixture until it is completely covered. Place the cinnamon-covered piece of dough in a cupcake liner.
Continue to dip each piece of dough in butter and then roll around in the cinnamon and sugar mixture. Place 3-4 pieces of dough in each muffin tin well, making about 10-15 muffins total.
Place the muffins in the preheated oven and bake for 18-20 minutes, or until the muffins start to turn golden. You don't want to overbake them because then they will be hard and crunchy; but if you don't bake them long enough you might have uncooked dough in the center. Keep an eye on them while they cook and once they start to turn golden on top, they should be finished.
Remove muffins from oven.
In a mixing bowl, combine powdered sugar and milk and beat together with a whisk or electric mixer. If you want your frosting to be a little thicker, add in more powdered sugar. Use a spoon to drizzle frosting over the top of each muffin. Because the muffins are so hot, the frosting will absorb into the muffins fairly quickly, so feel free to top with more frosting if desired.
Let the muffins soak up the frosting for a couple of minutes and then serve while the muffins are still warm. Enjoy!