In large skillet over medium heat, melt 1 tablespoon butter. Add squash, onions, garlic and cayenne pepper; salt and pepper to taste. Sauté until onions are golden brown (about 5-7 minutes).
Meanwhile, prepare gnocchi according to package directions; drain.
Add Alfredo, half & half, gorgonzola and sage to skillet. Bring to simmer, stirring occasionally; stir in gnocchi. Transfer to a greased 2-quart baking dish.
Melt remaining 1 tablespoon butter; toss with bread crumbs. Sprinkle over gnocchi. Bake in a preheated 375°F oven 25 minutes or until squash is tender and top is golden brown and bubbly.