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The taste maker

Arianna Halshaw, founder of Bittersweet Bakers, drinks a lot of coffee. “The coffee starts in that corner,” she says, nodding at her Gaggia Brera. “The first one of the day has to be a big slap in the face – a proper kick in the ass. I buy really nice beans and this brews a damn good cup.” She opens a bag of Monmouth’s Brasil Fazenda do Serrado and tips in the beans.

You’ll find Bittersweet’s kitchen in the shadow of The Shard, where trains scrape over the arches and weave through old estates and new-builds. Here Halshaw and her team bake cakes by the dozen for some of London’s most discerning cafés. The interior is light and airy, there’s a deep ceramic sink, a fresh green wall and neat stacks of cookery books. A radio hums on the windowsill.

Wake-up coffees brewed, Halshaw and her bakers tie bandanas over their hairnets and get cracking on orders for the six cafés that they bake for plus their regular customers and any ad hoc orders. The morning is fuelled by coffee. As well as enjoying the ritual of brewing, Halshaw drinks it throughout the day because it helps to balance the taste buds when you’re sampling as much sweet food as she does. As luck would have it, coffee’s a great palate cleanser.

Pen clipped onto her apron, she’ll lean right into the bowl she’s mixing, insert a blue-gloved hand and get stuck in. In the summer the bakers work into the evenings to avoid the morning sun that streams through the windows and plays havoc with sugar. “It’s impossible to do meringues in the heat,” Halshaw says.

Over by the ovens and the mixers, a large table serves as their workstation. This is where the magic happens. Bittersweet’s menu is extensive – there are fifteen variations of brownies alone – and cakes can be “fluffy and tender, or dark and sultry”. They have all kinds of crazy names to make you smile, and many of them contain coffee. I try the American Breakfast Biscuits (bacon, maple syrup, cornflakes, coffee) and Man Cake – a hard-hitting, smoky cardamom bake with a whisky icing and “gravel” topping. Their best-seller, the Everything Cookie, contains marshmallows, peanuts, coffee, oats, cornflakes and pretzels. “The menu is just a guide,’ she says. “We’re here to inspire you.”

Halshaw fell into baking for cafés “by accident” and thrives on relationships with people who appreciate the importance of all the little details that come together to create something really special. Her café clients have customers who are as obsessed with good cake as coffee. “When the coffee scene was taking off it was wonderful to see Londoners seek out coffee with such passion, discussing single origins and concentrating on a small luxury,” she says. “With a £5 spend on a brownie and a latté, it’ll be a good one. The London coffee scene has provided an outlet for that.”

She regularly checks in with each of her cafés, discusses their menu “to obsession” and always knows what they have in their hoppers. She studies the cupping notes to determine flavour profiles, then tailors a recipe to match the coffee exactly. “That way they’ll be made for each other,” she says. For The Coffee Works Project in Islington, she bakes fruit-based cakes to complement a coffee with crazy acidity and a syrupy sweetness. Her Brownie Cups for Clerkenwell’s Timber Yard are doused with the café’s espresso blend, Has Bean’s Jabberwocky.

She uses coffee in many of her recipes as a flavour booster. “Coffee isn’t necessarily the primary flavour,” she says, referring to a chocolate cake that contains a double shot of espresso. “It somehow makes the chocolate more chocolatey. It’s like the best supporting actress.”

In baking, the stronger blends tend to work better than light, citrusy ones. The intensity of coffee degrades with the heat of the oven, so you need a gutsy brew – Square Mile’s Red Brick is one she rates for baking because of its punchy flavour – and always need to add a bit more than you would expect. You also need to consider water content. You can’t add a brewed coffee to ganache, for example. Instead, freshly ground beans are added straight to the cream and infused before being strained out. Halshaw always uses her Porlex for grinding. “It’s nice to feel the beans grinding in your hand,” she says. “Grinding super-fine means you’ll get a more even spread of coffee throughout the bake rather than in pockets. You have to have excellent biceps in this kitchen. Do yourself the biggest favour and learn to do everything with both hands!”

Halshaw grew up in California – “where no one eats anything” – and would spend all her pocket money on cake mixes. Fast-forward several years and she found herself in New York studying at the prestigious French Culinary Institute, where she learnt about discipline and creativity – “What it means to hold a benchmark of quality,” she says. She hung out with other chefs and caught the food bug. Then she moved to London.

To make it as a pastry chef there are rules to live by. Being off with a measurement by even a small amount can make a huge difference. “You have to love that precision,” she says. “You have to be a Type-A personality who’s in love with their label maker.” Some days are production-focused, others more experimental. “Sometimes you get tasty accidents,” she says. “Something that tastes amazing but is completely unsellable.” Halfway through a recipe she might set some mixture aside and try out a new creation with it later. “We have some mad ideas,” she says.

Whenever she eats out in the evening, she’ll find herself dreaming up a way of recreating a dessert plate as cake or cookie. She thrives on chaos and creativity. “That’s the genius of baking,” she says. “Bending the culinary law. In this digital world you have to dig your heels in harder. I want a creative, hands-on part so that we’re still baking biscuits in a hundred years.” Bittersweetbakers.com

Jennie Milsom owns and runs With Jam and Bread
(020 8318 4040; 386 Lee High Road SE12) and is
the author of Café Life London (£12.99, available
from The Armchair Traveller at the bookHaus: hauspublishing.com)

Coffee and Walnut Blondie Cups

“Making these in a muffin or cupcake tin makes them easy to serve. Pop them into a lunch-box or even serve with a scoop of ice cream for a really indulgent treat or dessert. Again, the coffee is a main flavour component.”

260g plain flour

3/4 tsp baking powder

3/4 tsp bicarbonate of soda

1/2 tsp salt

225g unsalted butter, softened, plus extra for greasing

100g golden caster sugar

300g light brown or light muscovado sugar

2 large eggs

1/2 vanilla pod, scraped, or 1 tsp vanilla extract

175g good quality white chocolate chunks or buttons

125g walnuts, toasted and roughly chopped

2 tbsp freshly ground espresso coffee

Lightly butter a deep 12-hole non-stick or silicone muffin tin. Preheat the oven to 180ºC (170ºC fan). Sieve together the flour, baking powder, bicarbonate and salt. Set aside. Put the butter and sugars into a free-standing mixer with the paddle attachment and cream until light and fluffy. Add the eggs, one at a time, followed by the vanilla. Tip into a large bowl and fold in the flour mixture, followed by the white chocolate, walnuts and coffee. Spoon into the prepared tin and bake for 20-25 minutes until set in the middle (use a cocktail stick or press down lightly with your finger to test for firmness). Cool for 10 mins then carefully pop each one out of the cup and cool completely.

TIP: This recipe can also be made
in a 33cm x 23cm baking tray lined with parchment and baked for
30-40 mins

Espresso Brownie Bites

“This is a one-bowl wonder – a fudgey, chewy, brownie-like cookie. There are no eggs in this, so use a good quality, full-fat yoghurt to bind it all together. The coffee is more of a boost than the main flavour. These also make excellent ice cream sandwiches.”

215g melted butter

280g golden caster sugar

130g soft light brown sugar

270g full fat Greek yoghurt

2 tsp vanilla extract

110g cocoa powder

sifted 260g plain flour

sieved 1/2 tsp bicarbonate of soda

1/2 tsp salt

200g mini chocolate chips (53% cocoa solids)

4 tbsp freshly ground coffee

Preheat the oven to 180ºC (170ºC fan). Line two baking trays with parchment paper. Put the melted butter into a large bowl and fold in the sugars. Add the yoghurt and vanilla and fold to combine. Add the remaining ingredients and mix well. Using an ice cream scoop, scoop the mixture into 24 balls. Spread over the prepared trays and press down lightly with your hands. Bake for 12-15 minutes until firm – you’ll know they’re ready when they’ve lost their shine and started to crack a little. Cool for 20 minutes, then cool completely on wire racks. Keep stored in an airtight box or freeze for up to one month.

Espresso Millionaire’s Shortbread

“This is a new twist on the classic, with rich flavours, but is really easy to put together. The coffee here is the main flavour component – definitely more for adults and coffee lovers.”

For the shortbread base

210g melted butter

110g caster sugar

1 tsp vanilla extract

1/2 tsp salt

260g plain flour

2 tbsp freshly ground espresso coffee

550g ready-made dulce de leche (Bittersweet use the one by Porteña in Borough Market)

For the ganache topping

200ml double cream

2 tsp freshly ground espresso coffee

200g dark chocolate (70%)

75g white chocolate

2 tsp sunflower oil

coffee beans or white chocolate chips, to decorate

Preheat the oven to 180ºC (170ºC fan). Line a 33cm x 23cm baking tray with parchment paper. Put all the ingredients for the base into a mixer and cream together until the dough forms a stiff, paste-like ball. Press evenly into the prepared tin and bake for 25-30 minutes until firm. When completely cool, spread over the dulce de leche. Set aside.  To make the ganache, put the cream and ground coffee into a pan and place over medium heat. Heat until just before it bubbles, then remove from the heat and strain through a sieve over a bowl containing the chocolate and oil. Leave for 1 minute then whisk gently to combine until smooth. Pour immediately over the dulce de leche and smooth evenly over with a palate knife.  Decorate with coffee beans or white chocolate chips, then leave to set in a cool, dry place for 1 hour or until firm.