Preheat oven to 350°F
Brown the beef (or vegan substitute) in a large skillet over medium heat. Drain.
Return the meat (or vegan substitute) in the same pan, adding the spaghetti sauce. Add salt and pepper to taste. Simmer for 10 minutes.
Add about 1 cup of spaghetti sauce and meat mixture to bottom of 9 x 13 pan. Spread evenly.
Combine mozzarella and ricotta in a mixing bowl. Set aside 1/2 cup of the mixture.
Add 4-5 uncooked lasagna noodles on top of mixture.
Add cheese mixture on top of noodles, spreading evenly.
Add another layer of the spaghetti and meat sauce mixture on top of the cheese layer.
Add 4-5 uncooked lasagna noodles on top of the mixture.
Add cheese mixture on top of the lasagna noodles layer.
Add remaining spaghetti and meat mixture on top of the noodles.
Add remaining cheese layer on top of the spaghetti and meat mixture.
Cover tightly with foil and place in the oven for 1 hour.
At the 40-minute mark, add the remaining 1/2 cup of the cheese mixture to the lasagna. Place back into the oven for an additional 20 minutes.
Let cool 15 minutes before serving.