In a large skillet over medium heat, cook the ground beef until browned, about 5-7 minutes. Add the diced onion and sauté for 4-5 minutes until translucent, then stir in the minced garlic for another minute. Pour in the marinara sauce, crumbled bacon, Italian seasoning, smoked paprika, salt, and pepper. Let this mixture simmer gently for 10 minutes.

In a medium saucepan, melt the unsalted butter over medium heat. Once melted, whisk in the flour, cooking for 1-2 minutes until bubbly and golden. Gradually add the whole milk, continually whisking until the mixture thickens and bubbles, about 5-7 minutes. Stir in the grated Parmesan cheese and garlic powder, seasoning with salt and pepper to taste, then remove it from heat.

Preheat your oven to 375°F (190°C). In a greased baking dish, start layering the lasagna: spoon a layer of the meat sauce, followed by a layer of noodles, then a generous scoop of béchamel, and a sprinkle of mozzarella and cheddar cheese. Repeat the layers until all ingredients are used, ensuring the final layer is topped with a mix of remaining cheeses and a sprinkle of Parmesan for a golden crust.

Cover the baking dish tightly with aluminum foil and bake in the preheated oven for 30 minutes. After this time, carefully remove the foil and bake uncovered for an additional 15 minutes, or until the top is bubbly and golden. Once baked, let the lasagna sit for 10 minutes before slicing.