Cook pasta according to package directions for al dente., Meanwhile, in a Dutch oven, cook sausage over medium-high heat until no longer pink, 5-6 minutes, breaking into crumbles. Stir in tomatoes, garlic, fennel seed and pepper flakes; cook 1 minute longer., Add wine. Bring to a boil; cook until liquid is almost evaporated, 1-2 minutes. Stir in cream; cook 1 minute longer. Add spinach; cook and stir just until spinach is wilted., Drain pasta; add to sausage mixture. Stir in 1/2 cup cheese. Sprinkle with crushed croutons and remaining cheese.