Birthdays are brilliant, but why do they have to involve cake? asks Jo Malone

We're looking at the remmants of Keola's on-the-actual-day birthday cake. A swirly rainbow cake with a surprise burst of sweets inside, it looked amazing. But it was so sweet it was teeth curlingly gag worthy, it was like eating a huge handful of blue candyfloss while scraping a fork on a plate. It gave us the judders.

None of us like it but I don't like to just throw it away and there's clearly nothing natural about it as it refuses to go mouldy.

I keep offering it to anyone who visits, but I think adding a 'we really don't like it' and Keola pretending to be sick is putting people off. So it's just been sitting in its supermarket box, looking colourful, while I wonder what to do with it.

Keola's party with friends is coming up and she has her heart set on a blue and yellow lemon cake.

I'm pretty sure it can't be shop bought; I've not seen a lemon supermarket birthday cake, mind you it's hard to even find anything not covered in fondant icing – we don't like that either.

But making a cake that has to be seen by non-family is a big deal.

Keola's heard brilliant homemade birthday cake stories from number one daughter Sunny. I managed a very sad looking yellow cat once, and a reasonably upright tractor, but then top treasure friend Jenny stepped in and created unicorn and fairy castle marvels over the next few years.

More recently we've become rather fond of a shop-bought chocolate caterpillar.

I've tried since sad cat days but have had a few issues; the failsafe Wicklewood chocolate tray bake recipe shared at mother and toddler's isn't failsafe in our house and those photographs made out of icing need a reasonably tasting cake to sit on. One cake was so flat (and looked even worse in the morning than it had the evening before) that I had an emergency 7am dash for more ingredients to make another, which sort of worked when layered with the first.

But it's only an iced sponge, with lemon, it can't be that hard.

'We'll do it together,' I say.

'I'll help, it can be pink,' says Thalia.

Keola sighs…