2tablespoonschopped fresh basilplus more for garnish
10ozbox frozen spinachthawed and squeezed of excess liquid
MAKE SAUCE: In large saucepan over medium-high heat add olive oil. When shimmering add onions and cook, stirring often, until translucent and edges start to brown, about 4-5 minutes. Add garlic and stir constantly until fragrant, about 1 minute. Stir in tomatoes and oregano and bring to a bubble. Reduce heat, cover, and simmer for 10 minutes. Stir in basil, cover, and simmer for 10 more minutes. Season with salt and pepper.
COOK LASAGNA NOODLES: While sauce simmers, cook noodles as per package instructions until al dente. Drain noodles and transfer to pieces of parchment paper.
PREPARE FILLING: While noodles cook, preheat large nonstick skillet over medium heat. Add mushrooms and pinch of salt. Sauté, stirring often, until mushrooms release their moisture, about 2 minutes. Continue cooking mushrooms over medium heat, stirring occasionally, until moisture has evaporated and mushrooms have darkened, about 5-8 minutes longer. Transfer mushrooms to large bowl; set aside.
Pulse crackers in food processor until finely ground. Add cottage cheese, 1 cup mozzarella, Parmesan, basil, garlic, and ½ teaspoon salt and process until smooth. Transfer mixture to bowl with mushrooms, add spinach, and stir everything together to combine; set aside.
PREPARE PANS AND OVEN: Move oven rack to middle position and preheat to 375 degrees F. Lightly spray 2 9x13-inch pans with nonstick cooking spray. Spread 1 cup sauce into bottom of each pan.
ASSEMBLE: Spread about 1/4 cup filling onto each noodle. Roll noodles up, and nestle 6-7 rolls into each pan. Divide remaining sauce over top.
BAKE: Bake 15 minutes. Remove from oven, sprinkle evenly with remaining 1 cup cheese, and bake 10 more minutes. Garnish with chopped basil and serve.