In large bowl, mix together 0.75 cup crushed crackers, corn, tomatoes, chilies, onions, bell pepper, garlic, eggs, salt and chili powder with a fork until well blended. Add ground round and knead with your hands until mixed. Transfer to a lightly buttered, deep 3 litre baking dish. Sprinkle remaining half cup crackers over top and dot with butter. Bake in preheated 180ºC over about 1 hour, until center springs back when pressed with a finger. Makes 4 to 6 servings.