Step 1: Cook the bacon pieces in a large skillet over medium heat until crispy. Drain on paper towels, then crumble and set aside. Reserve 2 tablespoons of the bacon fat in the skillet.
Step 2: If needed, add olive oil to the reserved bacon fat in the skillet over medium-high heat. Add ground beef and chopped onion. Cook, breaking up the beef with a spoon, until browned and no pink remains, about 8-10 minutes. Drain any excess grease.
Step 3: Add minced garlic, salt, pepper, and oregano to the beef mixture. Cook for 1 minute more until fragrant. Stir in beef broth and marinara sauce. Bring to a simmer, then reduce heat to low and let it gently simmer while you prepare other components.
Step 4: If using traditional lasagna noodles, cook them according to package directions until al dente. Drain and rinse with cold water to prevent sticking. Lay them flat on parchment paper or a clean surface.
Step 5: In a medium bowl, combine ricotta cheese, sour cream, ranch seasoning mix, 1/2 cup of the grated Parmesan cheese, and half of the crumbled bacon. Mix well until everything is incorporated.
Step 6: Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish.
Step 7: Spread about 1 cup of the meat sauce evenly on the bottom of the prepared baking dish. Arrange a single layer of 3-4 lasagna noodles over the sauce.
Step 8: Evenly spread half of the ricotta cheese mixture over the noodles. Top with 1.5 cups of mozzarella cheese and 1 cup of cheddar cheese. Add another layer of noodles.
Step 9: Spread another 1.5-2 cups of meat sauce over the noodles. Top with 1.5 cups of mozzarella cheese and 1 cup of cheddar cheese. Add the final layer of noodles.
Step 10: Pour the remaining meat sauce over the top layer of noodles, ensuring they are well covered. Sprinkle with the remaining 1 cup of mozzarella and the remaining 1/2 cup of Parmesan cheese.
Step 11: Cover the baking dish tightly with aluminum foil. Bake for 25 minutes.
Step 12: Remove the foil and bake for an additional 20-25 minutes, or until the cheese is melted, bubbly, and lightly golden brown. If desired, you can broil for the last 2-3 minutes for extra browning, watching carefully to prevent burning.
Step 13: Let the lasagna rest for 10-15 minutes before slicing and serving. Garnish with the remaining crumbled bacon before serving.