Preheat oven to 350°. In a large bowl, beat the cake mix, milk and butter until blended (batter will be thick). Stir in nuts. Press half of mixture into a 13x9-in. baking pan coated with cooking spray. Bake 10-12 minutes or until set.
Place candies, cut side down, over crust. Drop remaining batter by tablespoonfuls over the top. Bake 25-30 minutes longer or until golden brown. Cool on a wire rack. Cut into bars.