In small bowl, mix cracker crumbs, Bisquick mix and sugar. Stir in butter until moistened. Press in bottom of ungreased 8-inch square microwavable dish. Microwave uncovered on High 1 minute 30 seconds to 3 minutes, rotating dish 1/2 turn every minute, until crust bubbles up slightly and then begins to flatten. Cool 10 minutes on cooling rack.