Next week, for DGD, I am doing a white sponge oblong cake with multicoloured numbers 14 through the centre, covered with marbled fondant in the same colours. Could you perhaps hide the children's initials inside the christening cake(s)? Or even make a letter shaped cake for each child?
www.bbcgoodfood.com/recipes/surprise-pinata-football-cake
This week I made a cake based on this idea, for DGS's 10th birthday.
January is a busy month for me, as last week I made a round cake for DD with coloured spots through the inside, decorated with butterflies. As you can probably guess, my latest experiments have been with 'surprise inside' cakes! I was running out of ideas after 15 years of baking for 6 GCs. Thank goodness for the internet!