How to Make It
Preheat oven to 400ºF. Cook macaroni in a pot of boiling salted water until just tender, about 2 minutes less than package label directs. Drain; return to pot. Off heat, stir in half-and-half, cheese, mustard, spinach and 1 tsp. salt.
Divide macaroni mixture among eight small ovenproof dishes. Sprinkle each with cracker crumbs. Bake until macaroni mixture is bubbling and cracker crumbs are golden, about 10 minutes.