Andrew Bowden, Hartsyard’s pastry chef and “plating guru” is offering something pretty special for special occasions. Responsible for Hartsyard’s offbeat desserts like the ‘big pile of mess’ pumpkin pie – a pastry-less spiced pumpkin purée beneath rice pudding and pumpkin seed sponge, poached pears and walnut praline – Bowden takes a similarly whimsical approach to his birthday cakes, and word of his exploits is slowly trickling through the grapevine. [fold]

Typically renowned for their modern American fare, the Newtown restaurant’s bespoke cake service started about 10 months ago. “We had one guy ring up from Melbourne who was coming here for his girlfriend’s birthday dinner, and I just took it from there,” says Bowden.

Following that first order, a malted chocolate mud cake came next for his brother’s birthday. It featured a chocolate biscuit base with Milo mousse layers laced with crushed Malteasers, topped with chocolate fudge, marshmallows and more of the choc-honeycomb balls. “It was a massive hit with everyone,” he says (the cake now forms one of a few core flavours available for diners and takeaway orders).

“To have all bases covered, I thought we needed a fruity one,” says Bowden. His raspberry cheesecake flavour has alternating layers of hazelnut dacquoise and vanilla sponge on a raspberry and hazelnut cookie base, between which is spread raspberry mousse, salted caramel mousse and lemon cheesecake, finished with salted caramel sauce.

Finally, there’s the peanut butter cake. For this one, a peanut butter cookie base sits beneath layers of banana cake stacked with passionfruit curd, peanut butter buttercream, banana cream and vanilla mousse, all covered with salted caramel, popcorn and peanut butter crunch. “I don’t make life easy for myself,” Bowden admits.

“The decorations are very spontaneous,” he says of the edible flowers, wispy toffee arcs, nuts and crumbled biscuits that might be used as finishing touches. It’s the generous blanket of ganache, curd or caramel allowed to spill over the cakes that’s his real signature: “That drizzle makes it look really delicious and extravagant.”

Before working in the kitchens of Summit and Wildfire, Bowden dabbled as both an art and engineering student – apt training for creating such intricate cakes and keeping them upright. While the themed ornaments that bedeck many of his cakes require a dense cake base and thick fondant icing, Bowden’s cakes are anything but heavy. “I like light cakes, so most of mine are based around a sponge and mousse,” he says, describing the risks of ending up with a melting cake landslide. “I guess I’ve just got some solid mousse recipes.”

The raspberry, chocolate and peanut butter cake flavours form Bowden’s go-to options, but there is still scope to have something unique created from a favourite ingredient. “I had one woman call up who said, ‘My boyfriend likes the burnt bits of banana bread. Can you do something like that?’” This tip-off resulted in layers of banana cake sandwiched together with salted caramel mousse and banana cream, complete with crunchy coffee biscuit, passionfruit curd and dehydrated banana cake pieces (mimicking the toasted flavour of over-baked banana bread) layered throughout. The topping saw a combination of brûléed halved bananas, popcorn dust and honeycomb nestled in amongst clusters of caramelised popcorn and even more salted caramel.

“Who doesn’t like to eat cake for a week after their birthday?” That’s Bowden’s rationale for creating cakes in two sizes: large for up to 10 people, and larger for 10 to 20. With so many components, his style of baking is quite the production. “You don’t want to see me when I’m making a birthday cake in the kitchen…I’ll have sponges on one bench, couple of mousses on that bench, all the stuff I’m going to throw into it, and it has to happen really quickly because the mousses start setting.”

Already handling Hartsyard’s full range of desserts, stealing hours seems the answer to delivering on Sydney’s birthday cake needs. “I get here at 10am, so there’s always from 6am to work on the cakes,” he says.

It’s the thrill of handing over something extravagant and completely unique that keeps him energised. “It’s massively exciting, people get all happy when they see that huge birthday cake.”