Preheat the oven to 400°F (200°C). Line a baking sheet with foil. Place sweet potatoes on it and prick all over with a sharp knife.

Bake sweet potatoes in the oven until tender when pierced with a knife, about 1 hour. Let cool enough to handle.

Meanwhile, place bacon in a cold pan over medium-high heat, and cook until fat begins to render. Reduce heat to medium and cook until browned and fully cooked.

Scoop sweet potatoes into a mixing bowl, discarding the skin. Mash into desired consistency with a spoon.

Add salt, black pepper, smoked paprika, egg, sour cream, green onions, half of the bacon, and two-thirds of cheese. Mix until evenly combined.

Spread the mixture evenly into a 2-quart shallow baking dish. Keep surface textured. Top with remaining bacon and cheese.

Bake casserole in the oven until the top is browned and edges bubbling, about 30–35 minutes.