In a large skillet over medium heat, brown the ground beef for about 5-7 minutes until fully cooked. Add in the diced onion, cooking until softened, about 3-4 minutes. Stir in the minced garlic and cook for an additional minute. Pour in the marinara sauce, and add the crumbled bacon, Italian seasoning, smoked paprika, salt, and pepper. Simmer the sauce on low for 10 minutes, then set aside.

In a medium saucepan, melt 3 tablespoons of unsalted butter over medium-low heat. Whisk in 3 tablespoons of all-purpose flour, cooking for about 2 minutes until golden and bubbly. Gradually pour in 2 cups of whole milk, whisking continuously until the mixture thickens, about 5-7 minutes. Stir in 1 cup of grated Parmesan cheese and 2 teaspoons of garlic powder, seasoning with salt and pepper to taste, then remove from heat.

Before layering your lasagna, preheat your oven to 375°F (190°C).

In a spacious baking dish, layer meat sauce at the bottom. Place 4 cooked lasagna noodles over the sauce, spread 1/3 of the béchamel sauce on top, followed by 1/2 cup of shredded mozzarella and 1/3 cup of shredded cheddar. Repeat this process twice more, finishing with a final noodle layer topped with remaining béchamel and the last of the mozzarella and cheddar, followed by ½ cup of grated Parmesan.

Cover the assembled lasagna with aluminum foil and bake in your preheated oven for 30 minutes. After this time, remove the foil, allowing the lasagna to bake uncovered for an additional 15 minutes, or until the top is golden and bubbly.

Once baked, let the lasagna rest for about 10 minutes before slicing. Garnish with chopped fresh parsley if desired.