How do you cut a custard square? Bakery goes viral with simple theory

By Checkpoint for RNZ.

An Australian bakery has whipped up controversy with its unconventional method of cutting custard squares.

Melbourne’s Ferguson Plarre Bakehouse has whipped up a storm in a coffee cup by revealing a seemingly unconventional way of cutting the notoriously oozy pastry treat.

More than 2.2 million people have viewed a video in which baker Steve Plarre turns the slice on its side to cut it in half, rather than cutting through the pastry layer on the top.

Using this method, “two lovely structures of pastry” stop the custard from escaping and making a mess, meaning that the slice retains its shape.

Plarre told Checkpoint that he was inspired to film the video after watching two diners “obliterate” a custard slice (also known as a custard square) while visiting bakeries in New Zealand recently.

“I should have just imposed myself on them and showed them how,” he says.

Plarre’s bakery sells between 1000 and 2000 handmade vanilla slices a day and he reckons it’s one of the most popular small cakes in Australia.

While some are hailing his unusual slicing technique as a genius move, Plarre says others can’t see what all the fuss is about.

“Most people say to me, ‘what on earth are you doing cutting your vanilla slice in half? Surely you’re eating the whole thing yourself?’”

What’s the right way to cut a custard slice on this side of the Tasman? It depends who you ask.

At Artcraft Bakery in central Wellington, baker Kheng Sam can see the wisdom of Plarre’s method, but he’s unlikely to use it. Custard slices are a big seller here too, and Sam uses a custard powder mix to ensure the slice contents aren’t too oozy.

“We use a small serrated knife and push down to cut through the pastry,” Sam says. “You have to bake the pastry right or it will become soggy from the custard and hard to cut.”

Suzi Bath, head of pastry at Auckland bakery The Daily Bread, agrees that the perfect custard slice is a nightmare to slice neatly.

Earlier this year Bath developed a high-end custard slice for The Daily Bread, mixing vanilla custard with whipped mascarpone and adding a layer of raspberry curd.

Her cutting method - using a small paring knife to cut through the slice while it’s still in the tin - raised eyebrows in her own team, but Bath insists it’s “the only way.

“We use a tiny serrated one to cut the pastry on top, and then a four-inch paring knife to cut through the rest. We cut it in the tin: we put a small paring knife in and drag from one side to another. That’s how I was taught when I first started out, but it definitely caused controversy in my team.”

Bath says the real issue with custard slices - also known as vanilla slices or ‘snot blocks’ by our friends in Australia - is when the custard is thick and rubbery.

“I think the softer the better, though it should still have some shape to it. You don’t want custard as solid as a brick to eat.”

Custard consistency is important, but good pastry is also key to an optimum custard slice experience, says Michael Kloeg of Clareville Bakery.

The Wairarapa baker, who has more than 20 years of experience, says puff pastry made with a high ratio of butter to flour is tender and easy to cut, which makes slicing through the layers much easier.

Kloeg agrees that Ferguson Plarre Bakehouse’s cutting method is a sensible one “if you’re sharing a custard slice, or eating one for dinner and dessert”. But Kloeg is no stranger to doing things differently: in 2020 he shared a video showing how to correctly eat a custard slice - splitting it in half and smearing the custard over both pastry layers. “We’ve actually got two complete meals here; we’ve got dinner, which is really healthy with a bit less sugar, and dessert.”

Custard slices aren’t taught as part of the repertoire for students at Le Cordon Bleu culinary school in Wellington and patisserie chef/lecturer Sam Heeney isn’t a personal fan of them either.

“I know they are a Kiwi classic, but I don’t think I’ve ever had a nice one,” Heeney says.

Le Cordon Bleu students learn to make mille-feuille, a close French cousin to the custard slice that features layers of puff pastry and crème diplomat (a mixture of custard and whipped cream).

Heeney says similar rules apply when it comes to cutting the two notoriously tricky pastries. She wouldn’t attempt either without a scrupulously clean and sharp knife, and a strong sense of eye appeal.

“I’d use a slight sawing motion with a serrated knife, and I always dip and clean the knife between each cut.

“I always aim to ensure that every slice is the same size and that it’s cut in the most appealing way for the customer.”