This isn't your grandma's pasta bake. Sure, it has the warmth, and maybe even the love of Grandma's (that's an ingredient only you can provide). But does Grandma add rich marsala wine, umami-packed mushrooms, and not one but two cheeses? Yeah, she loves you, but does she love you this much? (Yeah, she does. Call your grandma!)
Add pasta to boiling water and cook until al dente, 12-13 minutes.
Reserve ½ cup pasta water. Drain pasta in a colander.
While pasta cooks, prepare ingredients.
Prepare the Ingredients
Cut mushrooms into ¼" slices.
Peel and mince shallot.
Cook the Mushrooms
Place a large non-stick pan over medium-high heat with 2 tsp. olive oil. Add mushrooms to hot pan and cook undisturbed until lightly browned, 3-4 minutes. Then stir often until soft, 2-3 minutes.
Add shallot and garlic and cook until fragrant, 1-2 minutes.
Season with a pinch of salt and pepper. Add marsala wine, bring to a simmer, and cook until evaporated, 3-4 minutes.
Finish the Pasta
To pan with mushrooms, stir in pasta water and vegetable base.
Bring to a simmer and add pasta, spinach, butter, and Parmesan. Stir occasionally until slightly thickened, 3-4 minutes.
Remove from burner and season to taste with salt and pepper.
Bake the Pasta
Transfer pasta mixture to prepared casserole dish. For best results, use 9 by 13" casserole dish. You may also use a cast iron pan. Top pasta with Swiss cheese. Broil until cheese is browned and bubbling, 2-3 minutes. Remove from broiler.
Serve meal family style. Bon appétit!