Preheat oven to 400 degrees F. Spray a muffin pan with a non-stick spray and flour, or use muffin liners.
In a small bowl, combine the sugar and cinnamon and whisk well. Set aside 4 tablespoons of this cinnamon sugar to be used to sprinkle on the baked cruffins.
Open up all four puff pastry sheets and lay them on a flat surface. Set two aside for the moment, these ones will be placed on top.
Using a butter knife or offset spatula, spread the softened butter onto each of the bottom two puff pastry sheets. Using the larger cinnamon sugar mixture, generously coat the top of the first two buttered pastry sheets, covering the entire surface of each.
Take the other two pastry sheets that were set aside and place them on top of the cinnamon sugar sheets, creating a sandwich. Then, use a pizza cutter to cut 6 equal strips from each sandwich.
Next roll each slice up, like a cinnamon roll, and make sure to pinch the ends so the rolls stay closed while baking. Place each roll into a muffin cup and bake them for about 15-18 minutes or until golden brown.
While they are still warm, dip or sprinkle the cruffins in the remaining 4 tablespoons of cinnamon sugar, (or powdered sugar if you prefer) and serve.