Food: David Cameron's love affair with Colin (the caterpillar)

Two cakes Cameron: the birthday boy and his favourite Caterpillar

Taking to his new Twitter account, this week David Cameron uploaded a picture from the Tory party conference. "Thanks to my team for squeezing in a quick birthday celebration on this v hectic day," he wrote, alongside a photo of him behind two chocolate logs with candles.

Dessert fans will have recognised the logs as Marks & Spencer's Colin the Caterpillar birthday cakes, a delicious combination of chocolate sponge, chocolate buttercream and chocolate shell, finished off with a silly (chocolate) face.

Despite his obvious appeal to the under-10s, Colin has become a big hit with adults. And he's a staple in workplaces around the country; whenever it's a staff member's birthday, the office junior is dispatched for the mid-price, middle-class treat. "Despite Colin being a character that children love, he's become a firm favourite with grown-ups too," says M&S cake developer Helen Brennan. "We sell thousands of Colin cakes each week and he's achieved cult status across all age groups. We're glad that the Cameron family have such good taste!" I'm not sure you could credit Cameron with having "good taste", but it would appear he has a sweet tooth.