In my haste to publish my first post, I neglected to talk about the top of my Christmas cake and how I love to use pecans or almonds for decorations. Macadamias and walnuts are good too. You do not have to pre roast the nuts as they will cook slowly on top of the cake.
The nuts serve two purposes for me. One they are delicious and two they provide a cutting guide for slices! I like to make sure everyone gets a nut on their slice.