Crush toffee after freezing. Measure 1/4 cup and save for topping with cherries. Fold remaining toffee into whipped topping which has been tinted pale green with coloring. Cut cake crosswise into 2 layers. Spread bottom half, cover and then cover entire cake. Cut cherries into petal shapes. Add rest of toffee. Keep refrigerated until served. Serves 8 to 10.