It first started how most good things end: with a scoop of chocolate chip ice cream. Obviously I'd had ice cream before – I was six, after all – but the plastic cartons of luridly linear Neapolitan my grandma kept in the fridge for emergencies (which, after a few outings, usually only contained a sad strip of vanilla down the middle as both the chocolate and strawberry disappeared around it) could not hold a candle to this.

It arrived in a silver dessert coupe that was so cold it stuck to my grubby little paws when I reached out to take it from the waiter. We were at a café in Golders Hill Park in North London, a sweet little family-owned Italian cafeteria where we spent most Sundays – now, sadly fallen from its culinary glory days. It used to do a mean spaghetti bolognese, and round the side had an ice cream kiosk that, come rain or shine, had a queue of expectant children clutching sweaty pound coins outside it.

The first mouthful blew my tiny little mind, so much so that 24 years later, I can still remember exactly what it tasted like. To begin with, real chocolate. Not chocolate flavouring, or bastardised sugar-laced whey powder and cocoa claiming to have something to do with Belgium, but full-throttle dark chocolate that coats your mouth and fills your sinuses. The tannins simultaneously made me thirsty, yet adamant not to drink until I absolutely had to – lest any of the taste be washed away. Then, dense creaminess made light by the tingling coldness, and smoothness interrupted only by a welcome shard of frozen chocolate.

Not only do I remember that scoop, and the life-long love affair with dessert it no doubt initiated, but I remember what I was wearing when I ate it, what the weather was like that day and what we all ordered for main course. I didn't need Professor Marise Parent's neuroscience lab in Georgia State University to tell me that sweet tastes activate the part of the brain responsible for episodic memories (as the university revealed in November of last year), but now that it has, a lot of things have clicked into place.

Not only do I remember that scoop, but I remember what we all ordered for main course

Because, delve into Parent's research – which used rats that were fed a sucrose solution to prove the point – further, and it gets even more interesting. "Not only did we find that feeding the animals a 32% sucrose solution activated neurons in the dorsal hippocampus [where memories are formed]," she told me, "we found that the amount of activity in this area of the brain was inversely related to how familiar the animals were with the solution." Basically, the newer the sweet substance was to the animals, the more of a memory it formed. Finally! A bonafide, science-backed explanation for my Rain-Man-meets-Mr-Whippy abilities.

A lot is being made in the scientific community about the implications of this research on the obesity crisis; could, perhaps, ending a meal with something sweet forge a memory of that meal strong enough to stop us mindlessly ploughing into a bag of Kettle Chips an hour after we've eaten? The short answer is 'no'. "Our research doesn't say that sweet things can help control future intake," says Parent.

What it does say is that sweet tastes activate memory formation about the food itself and also about the personal experience of that meal: what, where and when something happened to you. What you do with that memory – whether you forget it and reach for a Crosstown doughnut or you're still waxing lyrical about a blob of ice cream decades after you ate it – is up to you.

This research does, however, tell us how vital that sweet hit at the end of a meal is to our memory and perception of everything that went before. Something London's finest pastry chefs have known for a while, long before anyone proved it in a lab. "Dessert is the completion of a meal. It refreshes your palate yet should also compliment what's come before," says Graham Hornigold, executive pastry chef for the Hakkasan Group.

"If you miss it, your dining experience remains incomplete." He says that, while the methods for making sweets might have changed (less refined sugar, less heavy cloying puds, more respect paid to elevating the flavour of natural ingredients), the joy they inspire should not. "One of my favourite creations was called simply 'the lemon pot.' It had a lemon base, mousse, lemon confit, lemon sorbet and crumble pieces," Hornigold explains. Each bite was different, evoking a lemon meringue pie, a lemon biscuit, a lemon sherbet sweet. It did what a dessert should do: transport you somewhere. Take you back to back to a time when life was less stressful than it is now."

This last point touches on another of the main reasons why burnt-out Londoners should not forgo sweets: nostalgia. A man who understands this all too well is Philippe Baranes, the restaurateur behind Dessance in Paris – pioneer of cuisine du sucre and the city's sole dessert-only restaurant. "I have a two-month-old son, and if I dip my finger in something sweet and give it to him, he smiles. The sweet taste is one we instantly like and it stays present throughout our lives, always associated with that same pleasure," he proffers, at the same time remonstrating that "sugar and sweet are not the same thing."

At Dessance, entire tasting menus are devised not of pastry and sugar-syrup creations, but of root vegetables and fruits made into staggeringly complex dishes that play teasingly on the boundary of sweet and savoury. Think warm potato emulsion laced with vanilla or beetroot purée with bergamot ice cream, cacao nibs and white chocolate.

Desserts are always the thing that create a lasting memory

This, too, is the direction puddings are heading in back home, and leading the charge is Kira Ghidoni, pastry chef at one of 2015's most critically acclaimed openings, Paradise Garage in Bethnal Green. "My two favourite desserts are based on vegetables – one using peas, the other artichokes. Londoners love sweet things – at The Manor [which is from the same stable as Paradise Garage], we have a dessert bar and lots of people come in just for that course. The dishes should delight, but also surprise. That's what diners want from a meal's final dish."

And she's right. I love a cheese board as much as the next girl, I really do, but despite the sugar backlash of the last two years and the gathering (and entirely merited, in my opinion) call for a sugar tax, desserts have always been the thing that tip the balance and create a lasting memory. Perhaps now, in an era where some will pay £30 for ingredients for a 'healthy' sweet-potato brownie (Deliciously Ella, we're looking at you), or get their sweet kicks from single-origin raw agave (other 'you won't believe it's not sugar' substitutes are available); at a time where drinking a glass of orange juice has become as passé as donning a Burberry baseball cap and using a Blackberry – it's time to make the sweet treats we do allow ourselves really count. ■

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