In a large skillet over medium heat, brown ground beef until no longer pink, about 5-7 minutes. Add diced onion and sauté until softened, approximately 3-4 minutes. Stir in minced garlic and cook for an additional minute, then add marinara sauce, crumbled bacon, Italian seasoning, and smoked paprika. Season with salt and pepper, then let the mixture simmer for 10 minutes.

In a saucepan over medium heat, melt unsalted butter until bubbling. Whisk in all-purpose flour to create a roux, cooking for about 2 minutes until golden. Gradually pour in whole milk while stirring continuously until the mixture thickens, around 5 minutes. Remove from heat and stir in grated Parmesan cheese and garlic powder, seasoning with salt and pepper.

Preheat your oven to 375°F (190°C). Lightly grease your baking dish to prevent sticking.

Start layering in the greased baking dish with a generous spoonful of the meat sauce at the bottom. Place cooked lasagna noodles over the sauce, followed by a layer of béchamel, then sprinkle with shredded mozzarella and shredded cheddar. Repeat layers until all ingredients are used, finishing with noodles and topping with remaining cheese and grated Parmesan.

Cover the lasagna with aluminum foil and bake in the preheated oven for 30 minutes. Remove the foil and bake for an additional 15 minutes until the cheese is bubbly and golden.

Once baked, let the lasagna rest for 10 minutes before slicing for easier serving.