In a large skillet, brown the ground beef over medium heat until fully cooked, about 6-8 minutes. Add the diced onion and sauté until softened, around 4-5 minutes, then stir in the minced garlic. Mix in the marinara sauce, crumbled bacon, and season with Italian seasoning, smoked paprika, salt, and pepper. Let it simmer for 10 minutes until flavors meld.

In a medium saucepan, melt the unsalted butter over medium heat. Whisk in the all-purpose flour, cooking for 1-2 minutes until lightly golden. Gradually add the whole milk, stirring continuously until the sauce thickens, which should take about 5 minutes. Remove from heat, and stir in grated Parmesan and garlic powder for a creamy finish.

Preheat your oven to 375°F (190°C). In a greased baking dish, start layering the lasagna: spread a layer of meat sauce, followed by cooked lasagna noodles, then half of the béchamel sauce, and top with shredded mozzarella and shredded cheddar. Repeat these layers, ending with a generous topping of cheeses and an extra sprinkle of grated Parmesan.

Cover the assembled lasagna with foil and bake for 30 minutes, then carefully remove the foil and bake for an additional 15 minutes until the cheese is bubbly and golden. The layers should be visibly set.

Once baked, remove the lasagna from the oven and let it sit for about 10 minutes. Garnish with chopped fresh parsley for an added pop of color, and serve!