Add onion, and green pepper to pan, and cook until onions are translucent, stirring often.
Add tomatoes, tomato paste, garlic powder, parsley flakes, oregano leaves, and bay leaf.
Heat to a simmer, and simmer uncovered for 20 minutes to allow seasonings to blend.
Meanwhile, cook lasagna noodles according to package instructions and drain.
In a large bowl, combine the chopped spinach, ricotta cheese, egg, shredded provolone cheese, 1/4 cup Parmesano Reggiano cheese, and white pepper. Stir with a large spoon until mixed well.
Preheat oven to 350° F.
Spoon 1/3 of the tomato sauce mix into 13" x 9" baking dish.
Cover with 1/3 of the lasagna noodles, and 1/2 of the Ricotta cheese/Spinach mix. Evenly spread 1/4 cup of the Mozzarella cheese, and 1/4 cup of the Parmesano Reggiano cheese.
Add another layer of lasagna noodles, and add the cheeses and 1/2 of the remaining tomato sauce as in the above step
Top with final layer of lasagna noodles, and top with the remaining tomato sauce. Spread sauce evenly.
Cover pan with aluminum foil, place on a large cookie sheet, place in oven and bake for 30 minutes.
Carefully remove aluminum foil, and bake for an additional 15-20 minutes, until cheese is melted thoroughly, and lasagna is bubbly.
Remove from oven, and let stand for 10 minutes before cutting into squares.