Cook tater tots in the oven according to package directions (alternatively, you can air fry or deep fry them according to package directions). These typically bake at 425 for about 18-20 minutes. Once the tots are cooked, set them aside and reduce the oven temperature to 400. Place 2 half sheet pans, or 1 large sheet pan into the oven, and preheat for 10 minutes.
Mix together ground beef, salt, pepper, garlic powder, onion powder, bacon bits, and shredded sharp cheddar until just combined (do not over-mix or it will result in tough burgers).
Form the ground beef mixture into little patties slightly larger than the width of the crispy crowns or tater tots (burgers will shrink a bit as they cook). This is about the size of the top of a shot glass. I typically use a teaspoon measure to scoop them, and form them into even, relatively flat patties so they cook evenly.
Cut the cheddar cheese for topping the baked burgers. You'll cut each slice into 6 equal squares, making 3 cuts crosswise and 3 cuts lengthwise to form 6 mini slices.
Transfer burger patties to the preheated baking sheet(s) and bake burgers for 3-4 minutes, flip, top with cheese and cook until cheese is just melted, about 1-2 minutes.
Assemble the mini cheeseburgers by adding caramelized onion jam to the top of a tater tot, then adding the cheeseburger patty on top, followed by a pickle chip and another tater tot. Secure each assembled burger with a toothpick.