In a large skillet over medium heat, brown ground beef until it's no longer pink, about 5 minutes. Add diced onion, cooking until softened, approximately 3 minutes. Stir in minced garlic for another 1 minute, then mix in marinara sauce, crumbled crispy bacon, Italian seasoning, smoked paprika, salt, and pepper to taste. Let the mixture simmer for 10 minutes, then set aside.

In a medium saucepan, melt unsalted butter over medium heat. Whisk in all-purpose flour, cooking for about 2 minutes until lightly golden. Gradually pour in whole milk, whisking continuously for 5 minutes until the mixture thickens and bubbles. Remove from heat, then stir in grated Parmesan cheese and garlic powder, seasoning with salt and pepper as desired.

Preheat your oven to 375°F (190°C). In a 9x13-inch baking dish, spread a layer of meat sauce over the bottom, followed by cooked lasagna noodles arranged side by side. Spoon a layer of béchamel sauce over the noodles, then sprinkle with shredded mozzarella and shredded cheddar cheese. Repeat the layers, ending with a final layer of noodles topped with the rest of the béchamel and a generous handful of mozzarella and cheddar.

Cover the baking dish tightly with aluminum foil and place it in the preheated oven. Bake for 30 minutes, then carefully remove the foil and bake uncovered for an additional 15 minutes. The top should be golden and bubbly, and the edges slightly caramelized. Once done, remove from the oven and allow the lasagna to rest for 10 minutes before slicing and serving.