This sauce is SUPER yummy as it is, but if you prefer to make it a bit lower-fat, lower-calorie option... just replace the béchamel sauce with marinara {homemade or store-bought}. You'll need a couple of jars. One for the bottom of the pan & one to drizzle on top of the manicotti {you may not need all of the second jar but you'll need more than one jar for sure!} Just heat the marinara in a medium saucepan over medium-low heat & add in HALF of the cooked, drained spinach as you would if you were making the cream sauce. Everything else is the same!