Preheat your oven to 375°F (190°C).

Heat the olive oil in a large skillet or medium saucepan over medium heat.

Add the diced onion and cook until translucent, about 4–5 minutes.

Add the minced garlic and cook for 30 seconds until fragrant.

Add the ground beef. Break it up and cook until browned and no longer pink, about 6–8 minutes. Drain excess fat if desired.

Stir in the diced tomatoes, tomato sauce, and 1 cup water. Add bay leaves, dried basil, granulated sugar, Italian seasoning, and salt. Bring to a simmer.

Reduce heat and simmer gently for 20–25 minutes, stirring occasionally, until the sauce thickens. Adjust salt to taste and remove bay leaves.

While the sauce simmers, mix the cheese filling: in a bowl combine ricotta, 8 oz grated mozzarella, 1/2 cup grated Parmesan, dried basil, dried parsley, and black pepper. Taste and add salt if needed.

Boil the lasagna noodles according to package directions until just al dente. Drain and lay flat on a lightly oiled sheet or towel to prevent sticking.

Spread a thin layer of meat sauce on the bottom of a 9x13-inch baking dish.

Lay down a single layer of noodles to cover the sauce.

Spread 1/3 of the cheese mixture over the noodles, then spoon 1/3 of the meat sauce on top. Repeat two more times.

Finish with a final layer of noodles, the remaining meat sauce, and sprinkle the remaining 4 oz of mozzarella evenly on top.

Cover the dish tightly with foil and bake for 25 minutes.

Remove the foil and bake for another 10–15 minutes until the top is bubbly and golden.

Let the lasagna rest for 15–20 minutes before slicing to help the layers set.