Preheat oven to 350° F. In a large 4-quart saucepan, melt 1/4 cup butter over medium heat. Add shallot; cook 1 minute. Stire in flour, sage, and 1/2 tsp. salt. Whisk in cream. Cooke over medium heat until thickend and bubble. Stir in corn.
Finely crush half the saltines. Stir into corn mixture along with eggs and sugar.
Transfer to 2-quart baking dish. Bake, covered, 15 minutes.
In a small saucepan, melt remaining butter. Crush remaining saltines; add to butter. Toss to coat. Top casserole with crackers and bake, uncovered, about 35 to 40 minutes more or until heat through.