Spinach Lasagna

Layers of tomatoes, spinach, cheese and pasta form a rich lasagna.
Prepare the lasagna a day ahead and bake just before serving.

Ingredients
Tomato Sauce
3 T Olive Oil
1 Yellow Onion
2 Garlic Cloves
28 oz Canned Diced Tomatoes
28 oz Canned Crushed Plum Tomatoes
1 T Tomato Paste
1/2 tsp Sugar
1/2 tsp Kosher Salt
1 T Dried Oregano
1 T Dried Basil
½ tsp Crushed Red Pepper
½ tsp Freshly Ground Black Pepper
Lasagna
2½ cup Whole Milk Ricotta Cheese
20 oz Frozen Spinach
1 Egg
9 No Boil Lasagna Noodles
1 lb Part Skim Mozzarella Cheese
⅔ cup Grated Parmigiano Reggiano Cheese

Directions
To prepare sauce, heat olive oil in a large saucepan. Add onion and garlic; cook until soft and translucent, but not brown.
Add tomatoes, tomato paste, sugar, salt, oregano, basil, crushed red pepper and black pepper; stir well. Bring to a boil; simmer, uncovered, 30 minutes. Let cool slightly.
Preheat oven to 375F.
To prepare lasagna, combine ricotta cheese, spinach and egg in a large bowl; mix well.
Coat the bottom of a 13 x 9-inch baking pan with a third of the tomato sauce. Cover sauce with 3 noodles without overlapping (break noodles to fit), half the ricotta mixture and half the mozzarella slices. Add half the remaining sauce, 3 noodles, remaining ricotta mixture and remaining mozzarella. Top with remaining 3 noodles, remaining sauce and Parmigiano Reggiano cheese. To make ahead of time, cover with foil and refrigerate 6 to 8 hours or overnight.
Place pan on baking sheet. Bake, uncovered, 40 minutes, or until bubbly. Let stand about 15 minutes before cutting into squares.