Place crackers on a lightly greased aluminum foil-lined jellyroll pan.
Bring butter and brown sugar to a boil in a saucepan, stirring constantly; cook 3 minutes, stirring often. Pour mixture over crackers.
Bake at 350° for 5 minutes. Turn oven off. Sprinkle crackers with chocolate morsels. Let stand in oven 3 minutes or until chocolate melts. Spread melted chocolate evenly over crackers. Top with pecans and white chocolate. Cool completely, and break candy into pieces. Store in refrigerator.