The duo want us to savour our sweet treats - as Ella Walker discovers.

A debate with Yotam Ottolenghi and Helen Goh on the merits of any particular cake, biscuit or pudding, spirals into serious, labyrinthine assessments of silkiness and nuttiness, crumb size and snap. (There is, they will tell you, an art to ensuring a biscuit has as much crunch when it's liberated from the oven as it does after three days in a tin).

You quickly realise they'd be utterly formidable on Bake Off.

Israeli-British chef Yotam, 48, co-owner - with Sami Tamimi - of the Ottolenghi delis and restaurants, and pastry chef and psychologist Helen, 51, have spent the last three years concocting and wrangling over sugary treats like this to include in their new book of desserts, Sweet. It's his sixth book and her first.

In it there are mini berry frangipanes, decadent cream-frosted puds and cookies galore - all of which have been put through the pair's ruthless, multi-stage recipe-testing regime. "Each recipe has to have something indefinably 'Ottolenghi' about it," says Yotam.

The perfect cake depends on the time of day

"Easy!" shouts Helen when asked to pick the bake she'd fancy a slice of right now. "The prune and Armagnac cake." (It has a rubbly walnut topping, dusted with clouds of icing sugar).

"It depends on the time of day, right?" ponders Yotam. "Now, I don't want anything creamy, I just want something that would be really nice with a cup of tea.

"But in the evening, something more dessert-y. I really love the - you know how much I like strawberries and vanilla - the rhubarb strawberry crumble cake..." We all glaze over in a sugar-spiked reverie.

"There was always going to be an Ottolenghi pastry book, the question was when," he adds, explaining how the Ottolenghi deli windows have become synonymous with sweet things, particularly the brand's huge and billowy meringues.

"Before you, no one had taken meringues seriously," Helen tells Yotam proudly.

Baking offers escape and brings back memories

The pair collided in 2006, when Helen, who hails from Melbourne, Australia via Malaysia, moved to the UK. She began by encouraging Yotam to up the patisserie and sugar-work in the deli windows, and won him over with her remarkable attention to detail and oaty Australian Anzac cookies. They've been friends and partners in pastry ever since - after all, "you don't eat a cake by yourself," says Helen with a grin.

With baking, it's the precision and escape that appeals to her: "There's a satisfaction of following the steps and then getting something at the end - just that sense of achievement, and that sense of flow. You have to be accurate and very focused, which means you forget about everything else."

For Yotam, it's the way baking intersects with memory: "We're all yearning for things that feel comforting and reminiscent of home - and I think baking really brings that across, even more than other forms of cooking."

"And we feel a bit disjointed about our reality [at the moment]," he adds thoughtfully, "with so much of it not being real, so much of it happening on computer screens and TV screens. I think baking just creates that sense of place, of home."

Demonizing sugar makes you want it more

One thing they were highly aware of throughout making Sweet, was the negative conversations being had around sugar - the mainstream demonization of the white stuff.

"The difficulty at the moment is creating a clear understanding of what you expect of sugar," says Yotam. "Whenever you demonise something, you want it even more; it creates an unhealthy relationship."

"We've always been raised eating a little bit of sugar, but somewhere along the way, that relationship has become a little bit broken," he says, explaining how a bewildering distance has opened up between us and sugar: "It's mainly to be blamed on mass-produced food, and sugar added where it doesn't need to be, so how are you meant to trust your instincts on it now?

"There is room for a piece of cake, room for a bar of chocolate - there is room for all of these things in our lives - but we need to do it consciously."

Know what you are eating and relax a little

"It's about savouring what you eat," Helen agrees.

"And if you make it [yourself], you know exactly what goes in - you are much more aware of what you're eating," adds Yotam. "I think generally we should be a little bit more relaxed about everything, and the rest will follow."

HOW TO MAKE YOTAM

OTTOLENGHI’S BLACKBERRY

AND STAR ANISE FRIANDS

Created by Yotam Ottolenghi and

Helen Goh, for their new cookbook,

Sweet, they say: “These look

splendid when iced - destined for top

ranking on any tiered cake stand -

but also work un-iced, in the cookie

tin, for grabbing on a whim.

Ingredients:

(Makes 12)

180g unsalted butter, plus an extra

10g, melted, for brushing

60g plain flour, plus extra for

dusting

200g icing sugar

120g ground almonds

1 1/2tsp ground star anise (or 3

whole star anise, blitzed in a spice

grinder and passed through a finemesh

sieve)

1/8tsp salt

150g egg whites (from 4 large eggs)

Finely grated zest of 1 small orange

(1 tsp)

18 whole blackberries (about 120g),

cut in half lengthways

For the icing (optional):

60g blackberries (about 8), plus

an extra 24 small blackberries, to

garnish

3/4tbsp water

1tsp lemon juice

165g icing sugar

Method:

1. Preheat the oven to 220°C/Gas

Mark 7. Brush the 12 holes of a

regular

muffin tin with the melted butter

and sprinkle all over with flour. Tap

the tray gently to ensure an even

coating of the flour, then turn upside

down to remove the excess. Place in

the fridge to chill while you make

the batter.

2. To brown the butter, place in

a small saucepan and cook over a

medium heat until melted. Continue

to cook until the butter is foaming,

gently swirling the pan from time

to time, to allow the solids to brown

more evenly. You will see dark

brown sediments begin to form on

the sides and bottom of the pan.

Continue to allow the butter to

bubble away until it turns a rich

golden brown and smells of toasted

nuts and caramel. Remove the pan

from the heat and let it stand for

five minutes, to allow the burnt

solids to collect at the bottom of the

pan. Strain through a fine-mesh (or

muslin-lined) sieve, discarding the

solids. Allow the browned butter to

cool slightly before using.

3. While the butter is cooling,

sift the flour, icing sugar, ground

almonds, star anise and salt into

a bowl. Place the egg whites in a

small bowl and use a whisk or fork

to froth them up for a few seconds.

Pour the egg whites into the sifted

dry ingredients and stir until

incorporated. Add the orange zest

and browned butter and mix until

smooth.

4. Remove the muffin tin from the

fridge and fill the moulds just over

two-thirds of the way up the sides.

Place three halved blackberries on

top, cut side down, and bake for 10

minutes. Reduce the temperature

to 210°C/Gas Mark 6, turn the tray

around in the oven for even cooking,

and continue to cook for another

eight minutes, until the edges of

the friands are golden brown and

the centres have a slight peak and

spring back when gently prodded.

Set aside to cool before removing

them from their moulds.

5. If you are icing the cakes, place

60g of blackberries in a small bowl

with the water and lemon juice.

Use a fork to mash them together,

then pass the mixture through a

fine-mesh sieve to extract as much

fruit juice as possible - you should

get about 60ml. Sift the icing sugar

into a medium bowl, pour in the

blackberry juice and combine to

make a light purple runny icing.

It should just be thick enough to

form a thin glaze on the tops of

the cakes. Spoon the icing over the

cakes, spreading it to the edges so

it runs down the sides. Place two

small blackberries on each friand,

set aside for 20 or 30 minutes to set,

then serve.

*Sweet by Yotam

Sweet by Yotam Ottolenghi and Helen Goh is published by Ebury Press, priced £27. Photography by Peden + Munk. Available now.