It might be really hard (or impossible) to spread. You could heat it and pour it out in a pan filled with parchment paper and cool it the shape you'll be using for your cake, so you can just plop it on and peel the paper off.

plllog's idea sounds about right

Any topping that pours at room or refrigerator temperature will just keep pouring, right off the cake, unless everything is very, very cold as you assemble the cake.

Enjoy

I've gone for a Snicker's effect, chocolate and caramel topping, and chopped peanuts. Have also added chopped toffee bits, and once, even mixed peanut butter in with the chocolate topping.

Put the ice cream bars back into the freezer as you unwrap them. Have everything else ready to go, then just pull the ice cream bars out and assemble. Store it in the freezer until just before serving.

It's very forgiving (and plus, my co-workers will eat anything, not caring if the topping is a little runny, it's a little too frozen, too chewy, etc.)

You folks are the best! Nowhere else would I have received answers that fast. The cake is for my Canasta players tomorrow and I suspect they will eat most anything sweet, so I bit the bullet and spread the caramel on top of the frozen chocolate, then refroze before adding the whipping cream and more layers. It seems to have worked. If I can only keep it in the freezer when it isn't being eaten tomorrow. Thanks!

Zela