Preheat oven to 375°. Break cauliflower into medium size pieces. Place in microwave safe dish with butter. Microwave, uncovered, on high for 10 minutes; stir to coat. Microwave an additional 8-10 minutes or until cauliflower is tender. Drain. Stir in ½ cup cheese and dip mix. (Reserve 1-2 tsp. dry mix for the cream cheese layer.) Pour into 8 x 8 baking pan. Combine cream cheese, ½ cup cheese, salsa and rest of the dry dip mix in microwave-safe dish. Microwave until well softened; spread over cauliflower and top with remaining cheese and sliced jalapeños, if desired. Bake 20 minutes or until cheese is melted.