Preheat the oven to 425 degrees F. Grease the cups on a mini muffin tin with non-stick cooking spray.
Place three tater tots in each muffin tin cup. Bake for 10 minutes.
After 10 minutes, remove the muffin pan from the oven and use a tart tamper to press the tater tots down into each cup. (You can also use a muddler or the back of a measuring spoon.) This will form the tater tots into a cup shape to hold the toppings.
Fill the tater tots with the cheese and bacon (or whatever toppings you like).
Place the tater tots back in the oven. Cook for another 15 to 20 minutes or until the tots are golden brown and the cheese is melted.
Remove from the oven and let cool for at least 5 minutes. Drizzle ranch dressing over the tots and sprinkle with green onion before serving.