Line a 9” X 9” baking pan with parchment paper or foil.
In a large bowl, prepare pudding according to package directions, by mixing pudding mix with milk and whisking for two minutes. Whisk in cake mix. Stir in chocolate chips and toffee bits. Pour into prepared pan and bake for 45 minutes or until middle springs back when lightly touched. Blondies should still be slightly loose in the middle when pan is shaken.
Let cool in pan completely before frosting.
For the frosting:
In a large chilled bowl beat whipping cream until soft peaks form.
Alternately add pudding mix and icing sugar and continue beating until frosting is spreadable consistency. If too thick add milk one tablespoon at a time.
Spread frosting on top of cooled blondies and top with remaining 1/4 cup of toffee bits.