Place the broccoli and corn in a large bowl. Add the 1/2 cup crushed crackers, the cheese, whipping cream or half-and-half, egg, the 2 tablespoons butter or margarine, the onion powder, salt, garlic powder, and pepper.
Stir to combine the mixture. Spoon the mixture into a 1-1/2-quart round casserole or a 9-inch pie plate.
Sprinkle the remaining 1/2 cup crushed crackers evenly over casserole.
Drizzle with the remaining 2 tablespoons melted butter or margarine.
Bake, uncovered, in a 350°F oven for about 25 minutes or until the edges are bubbly.