Preheat oven to 375F. Coat a 9-inch square or a 10x8" pan with cooking spray.
Combine the almonds, walnuts, onion, garlic, basil, nutmeg, salt, pepper and water in a food processor and process until smooth, about 1 minute.
Spread 1/2 cup of the marinara sauce on the bottom of the pan. Cover with half of the uncooked noodles, spinach, tomatoes and nut mixture. Repeat the layers again and transfer to oven. Bake for 50 minutes, until lightly browned.
*For baked rotini, use 4 ounces fiber-enriched or high-fiber rotini, such as Barilla Plus or Barilla Whole Grain (four ounces is about 1 heaping cup dry). Cook pasta according to the package directions. In a large bowl, combine all the ingredients except the marinara sauce. Cover the bottom of the pan with 1/2 cup marinara sauce, top with the pasta mixture and finish with the remaining 1/2 cup marinara sauce. Bake for 40 minutes, until lightly browned.