Place the diced Yukon gold potatoes into a large pot and cover with cold water by 1 inch. Add 1 tablespoon of fine sea salt. Bring to a rolling boil over high heat, then reduce to medium-high and simmer for 8 to 10 minutes until just fork-tender but still holding their shape (do not overcook into mash). Drain thoroughly in a colander and let steam dry for 5 minutes.

Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch ceramic baking dish with butter. In a large mixing bowl, whisk together the softened cream cheese, sour cream, melted butter, heavy cream, minced garlic, smoked paprika, garlic powder, onion powder, sea salt, and black pepper until completely smooth and velvety.

Gently fold the drained warm potato cubes into the creamy sauce using a wide spatula or wooden spoon. Fold in 1.5 cups of the shredded sharp cheddar, all of the Monterey Jack, half of the crumbled beef bacon, and half of the minced chives. Spread the mixture evenly into the prepared baking dish.

Top the casserole evenly with the remaining 1 cup of sharp cheddar cheese and the remaining crumbled beef bacon. Bake uncovered at 375°F for 25 to 30 minutes until the cheese is melted, bubbling vigorously along the edges, and golden brown on top. For extra color, broil on HIGH for 2 minutes. Rest for 8 minutes before garnishing with fresh chives and serving.