Christmas Cake Decorations that Kids Love-Frost a cake blue and draw a snowman or snowflakes on the cake with white or icy-blue icing. Outline a snowman with black icing on a white frosted cake. If you don’t have time for this, you can buy icing decorations from cake shops.You can use candy shapes for festive Christmas cake decorations. Incorporate seasonal candy and it doesn’t matter if you’re making a Christmas cake for children or adults. Everyone is sure to love it!