Bring the oil to a simmer in a pot. While it's heating up, crush the onion-flavored rings and cheese puffs into crumbs with a food processor or a mortar and pestle. Transfer to a shallow dish, add about 1/2 cup water and stir to make a batter. Scoop out a spoonful of mac and cheese and dip it in the batter. Deep-fry it in the oil until it develops a crust, about 5 minutes. Place each mac and cheese morsel on a cracker. Add a drop of hot sauce if you'd like to spice things up.