Hi - it's me - with my 2 cents!
You can always try this:
Line your pan (pick a pan, bowl, plastic container, mold - your choice) and line loosely with plastic wrap - a double thickness is best. Be sure to leave enough to grab on to.
Now you fill with your softened ice cream and or sherbet, layering flavors or placing ice cream toppings or fruits or candies or nuts or marshmallow creme in between layers or here and there.
Next - you top your ice cream with graham crackers, cookie crumbs, crushed nuts, candy bars - whatever.
Freeze.
Yeah I know - your bottom is on the top - so just hold on a minute -
When completely frozen - invert onto serving dish and lift plastic - pan should release with no trouble. Peel off plastic wrap.
Okay - now you've got the "wrinkles" in your ice cream cake.
So what do you do????
You can soften ice cream and "frost". Decorate with any fruits, candies, maraschino cherries, etc. Use your imagination. Re-freeze.
You can press crushed nuts into the top and on the sides.
You can pour Magic Shell over the cake as an "icing". It hardens nice and glossy. Sprinkes look good on it too.
You can drizzle melted chocolate all over the top and let it dribble down the sides.
You can buy those mini cookie packs and press them half way into the cake - nice if using chocolate chip, nutter butter or oreos as a base.
You can just sprinkle jimmies on top - or other decorative candies.
You can use any dish or bowl, mold or casserole.
Use a bowl and make a half baseball using vanilla ice cream and red licorice for the stitches; use a plastic football tray or a casserole dish for a football (frost with chocolate ice cream or make the cake out of chocolate ice cream); use coffee cups for smaller ones or muffin tins of any size (the mini ones are nice - time consuming - but nice little poppers) - the list is endless! You'd be surprised at all I have created!
Just thought I'd pass on a few ideas...................