These large cakes in Aldi are €3.99 and make great birthday cakes if you use your imagination, one here I did for the number 7 and decorated it with sweets by sticking them on with icing (ready made icing tubes €1.50 in Dealz) the other one I did was I bought a Tescos own brand choc cake and decorated it with choc fingers and sweets etc (would be even cheaper if you can make your own, I’m not a big baker so this worked out cheap for me 😉 Lidl do a white chocolate one too, if the kids aren’t big cake fans then you can also do this with ice cream by letting a tub or 2 of ice cream soften and adding it to bowl, mix in what bits you want like fudge, smarties, meringue, sweet sauces etc and then adding it to a lined baking tin to reshape and refreeze until needed, you can decorate on the day if you take it out of the freezer a bit in advance so the sweets stick to the softened ice-cream top etc