Why cake bakers are making whoopie

The whoopie pie, said to date from the 1920s, was first made by Amish farmers' wives from leftover cake batter as a lunch-time treat for their husbands, who ploughed the fields of Pennsylvania. When they spied the cakes in their lunch packs, they would shout: "Whoopie!"

Since then, they have become a staple in the American sweet cupboard. They even have an annual festival held in their honour in Pennsylvania.

Natalie Allen of Sweet Things (www.sweetthings.biz) is one of a small but growing number of UK outlets - including the Hummingbird Bakery and Harrods - which started selling whoopie pies before M&S cottoned on. Retailing at £1.75 each, she reckons her sweet pies will take over from the cupcakes as the last word in sweet trolley-chic at barmitzvahs and wedding anniversaries.

"I always look to American websites to see what the latest trends are over there," says Allen, who supplies posh food hall Fortnum & Mason and whose brownies are a favourite with Nigella Lawson. "That way, I get them before they reach the UK. I had absolutely no idea what they were so I had to do some research. I always describe them as a cookie sandwich. They're totally different to a cupcake. They have quite a salty, sour sponge. When people see them they say, 'Oh wow, what's that?'"

Allen does just the original flavour - chocolate - with a gooey vanilla cream in the middle. The lightness of her sponge is due to a batter is made with bicarbonate of soda and not baking powder, which is crucially different to the cupcake. And there we all were thinking that raising agents were interchangeable.

The icing - or frosting as they call it in the States - is made with an American confectionary item that comes in jars - Marshmallow Fluff. That, and the lack of egg, makes it lighter than regular butter cream. To finish, Allen adds just a sprinkling of glitter on top, rather than what she believes would be a cloyingly sweet icing. The overall experience is one that is neither too sweet nor too filling but full of American style flavouring.

The whoopie pie certainly has advantages over its prim cupcake friends. Rather than getting the (often copious amounts of) icing up your nose before reaching the cake below as you do with a cupcake, the cream in a whoopie pie is neatly contained within the two mounds of cake - rather like the meat in a burger. And they are much less fiddly to make if you keep them simple, which is the way they are supposed to be.

But of course, some places just cannot help making things more elaborate. The Hummingbird Bakery has turned its whoopie pies into a posh affair with red velvet and pumpkin flavoured sponges both with cream cheese filling varieties going from £3 each. Harrods does a cherry fondant flavour decorated with silver pieces and cherry hearts. Theirs are £2.50 each.

Where Harrods leads others follow so it will not be long now till everyone is making whoopie.