Preheat oven according to french fry package directions (typically 400-450 degrees).
Spread french fries in a single layer on a baking sheet. Bake a few minutes longer than package states so they're extra crispy (I bake my thin-cut fries at 450 degrees for 20 minutes). Remove from oven and lower oven temperature to 400 degrees.
Sprinkle garlic powder, cayenne, and pepper over the fries. Toss to coat.
Transfer half the fries to a cast iron skillet. Top with ¾ cup of shredded cheese and crumble three strips of bacon over fries.
Add remaining fries to skillet and top with remaining cheese and remaining crumbled bacon. Put skillet in oven for 4-5 minutes, until cheese is melted.
Remove from oven and top fries with remaining ingredients: tomatoes, jalapeño, sliced avocado, scallions, sour cream, and any other desired ingredients.