How to Make It
Preheat oil to 400°F in a large saucepan over medium-high.
While oil preheats, use a 1-in. cutter to cut a hole in the center of each uncrustable. Press edges around center of hole to seal sandwich closed in the middle.
Fry each sandwich in hot oil until browned, 8 to 10 seconds per side. Drain on paper towels. Stir together sugar and cinnamon on a plate; dredge donuts lightly in cinnamon sugar.