I apologize that I didn't include more information in my original post.
In the past I have made an ice cream cake using crushed chocolate sandwich cookies as a base with a layer of chocolate ice cream, chocolate crunch pieces, a layer of vanilla ice cream, more chocolate crunch and a final layer of chocolate ice cream all topped with whipped cream.
A friend has asked for a similar cake for their birthday but with maple walnut ice cream. I am looking for a complimentary taste to use as the base and/or to layer between the ice cream. It can be the same for both the base and filling or something different. I am making the cake as as their gift so the choice of fillings has been left to me.
Thank you, and again, my apologies for leaving out important information in my original post. That's what I get for trying to post when I am having a sleepless night!