Fry the bacon in a sauté pan until crisp. Remove the bacon while reserving ½ tsp of the bacon oil. Chop the bacon into fine pieces.
Sauté the spinach in the same pan as the bacon until it is wilted. Let it cool, then coarsely chop.
Preheat the oven to 375°F.
Place the cream cheese, sour cream, cooked spinach, bacon, garlic, salt, pepper, chili powder, parmesan cheese, hot sauce, and ¾ cup of mozzarella cheese in a bowl. Stir until well combined.
Spread the spinach mixture into a baking dish. Top with the remaining mozzarella cheese.
Bake for 20 minutes or until the dip is bubbly and the cheese is melted. Turn the oven to broil and cook until the cheese starts to brown.
Serve with Garlic Bread Crostini