Kim-Joy’s house lies down a wiggly lane between Leeds and York, “a mystical place off the radar,” she says. Right now, it is full Bake Off, her table taken up by the giant “goodbye” cake contestants are given when they leave (she came joint second, of course), her shelves laden with different flours, in chic, labelled glazed pottery. The kitchen gives out on to huge fields at the back, a completely undreamed of scene of peace, with the world’s two free-rangiest chickens. “I think my neighbour might have a horse,” Kim-Joy says, dreamily. “How can you think someone might have a horse?” I ask. She gives me a smile as warm and perceptibly calm as the one that had such a soothing effect on the Bake Off tent, uncurdling every dicey batter.

I’m not saying Rahul shouldn’t have won Bake Off; he has distinctive qualities of his own. But Kim-Joy is such an unusual person for the public eye, so self-effacing, so restrained and undramatic, give or take the eyeliner, that she could have had a prize in her own category: Balm to the Nation’s Psyche.

“People who are bakers always tend to be nice people, just because they want to give to other people,” she says, and it’s true – you don’t see many people making cakes for themselves, except in romcoms. “How can you bake and not be nice?” she adds.

That is perhaps what drives Bake Off, the delightful contradictions of making competitors out of people who, by their nature, collaborate; yet this isn’t the first niche competitive scenario to change Kim-Joy’s life. She is also into board games, and recently came second in a Splendor tournament. The board-games world “is quite male dominated,” she says, “so if you look really girly, people think you don’t know what you’re doing.” This is how she met Nabil, her partner, the inspiration behind the bee-decorated doughnuts she made on the show. He owns four board-game shops in the centre of Leeds, and she met him at a board-game club night, because, yes, those really exist.

They played board games for a year and a half before anything happened – “Azul, that’s quite a good strategic game” – and he got to know of her fondness for baking, and “mentioned to me casually one day: ‘It’d be really nice if you made something for me.’ And I was all casual, too, and said: ‘I’ll do that sometime.’ And I came in the next day with my bread. It was a brioche, a couronne, filled with sun-dried tomatoes and basil. I was sharing it round everybody and he didn’t think they were appreciating it enough. And he said: ‘I want all this for me.’” It’s like a love story co-written by Jilly Cooper and Delia Smith.

Facebook Twitter Pinterest Kim-Joy and fellow finalist Ruby Bhogal applaud Bake Off winner Rahul Mandal. Photograph: C4/Love Productions/Mark Bourdil/PA

Her home’s other recurring theme, besides the baking, is the Japanese animation, My Neighbour Totoro, with illustrations of the giant grey-furred woodland sprite everywhere. They also remind her of Nabil. “I thought he reminded you of a bee?” I say. “He reminds me of a lot of cute things,” she says.

Kim-Joy became known on the show for her intense commitment to cuteness: anything that could be an animal would be; she could see the rabbit potential in every shape. She won star baker in vegan week with a lavender and lemon cake decorated with foxes, alongside some squirrel tartlets. Then there was her galaxy-themed chocolate ball that melted to reveal a gang of space turtles carrying tiny umbrellas. Her famous bunny madeleines in the semi-final were so dinky, it felt like vandalism to watch one disappear into Paul Hollywood. But the genius of the casting is that, from the first episode, it always looked as if there was something real underneath, that it was a kind of cartoon generosity, not tweeness, driving it.

Her other star baker week was the spice round. Ginger biscuits are a risky game: make them once and everyone calls you a genius; make them twice, and everyone says you’re playing it safe. She makes them a third time, for me, in animal shapes (of course), and it all happens so smoothly that, from where I am standing, it just goes from a clean kitchen back to a clean kitchen that smells of baking ginger, without any mess in between. To watch her decorate is mesmerising, tiny piping bags of royal icing lined up like fat little fondant mice, delicacy and perfectionism shot through with zen-like chill.

Before Bake Off, Kim-Joy was a psychological wellbeing practitioner, having done a master’s in psychology. “The technical job role was to help people with low to moderate anxiety and depression,” she says. She is always careful not to come across as critical, and never more so than when she talks about her work. “I love the NHS. I really want to work in the NHS, but I’m at a point where the clinical side of mental health isn’t for me. You do a questionnaire with each person when they come in. So they tell you how many times that week they’ve felt low, which is a really weird question. It’s not real. Professionals need it for their data, to see who’s recovering. A lot of people just make up their answers, because they want to sound like they’re feeling better.”

The people she saw were limited to six half-hour sessions, and many more were classed “severe” than “low to moderate”; she had 150 people on her books at any one time. It is a classic story of stretched services, but having been in the caring professions all her life – she worked in a care home when she finished her first degree, in sociology, at Bristol – she has seen the limitations at close range. She says the care-home role “was terribly paid and the management were terrible. [But] I ended up really liking the residents.” Then she settled in Leeds, and did support work in the community to fund her master’s, mainly for adults with learning disabilities.

She is at a crossroads, wanting to carry on working in mental health, but “there’s a big emphasis on diagnosis, and I know there’s a place for diagnosis, but a lot of the time, people don’t fit into those boxes. And it’s helpful, so that people can get the right treatment, but not if the diagnoses don’t fit. I’d love to combine baking with mental health. Art therapy is a thing, isn’t it? Why not baking therapy?”

Facebook Twitter Pinterest ‘Art therapy is a thing – why not baking therapy?’ …Kim-Joy gets icing. Photograph: Christopher Thomond/The Guardian

She has done very little work with children, so it was a Bake Off revelation to discover that “quite a few children seem to like me. I’ve had so many drawings from children. I didn’t really see that coming.” I suggest it is because she is quite high-energy without getting in your grill, which children like but adults can’t often manage. “I think I’m quite low-energy, generally. I just like to chill and be at home and bake. It’s just because you’re here, I’ve put some energy on.”

The animals she has made – well, a cat, some stars, I think it’s a bell and her signature turtle – are out of the oven, but need time to cool before icing. She was born 27 years ago to an English father and Malaysian mother in Belgium, but that’s not the source of her patisserie skill: she moved back to the outskirts of London aged nine, none of her family bakes, and she didn’t really take it up until she went to university. “All I remember of baking as a kid was having to make mince pies, which I really hated. So it’s not really a fun baking story.” She started in earnest, she says simply, because: “If you make something, it makes people like you. It’s just about making people happy, I guess. I got into the decorative side of it later.

I started making friends by baking. And I’ve got a lot more normal as time’s gone on

“I didn’t really speak when I was at school, I was pretty much mute. I would talk at home, and sometimes I whispered to people, but I was very careful about who could hear me talk; I didn’t want people to know that I could. I would say it was severe social anxiety. There’s selective mutism as well, but a lot of that is in really young children, and this was at secondary school. So I don’t know if I fit the criteria. But I don’t really believe in criteria anyway. I was always trying to break out of my shell because I knew that wasn’t really me. But who was?”

That carried on at university, where she chose a course almost at random, and went off, hoping to throw herself into socialising. “I thought: ‘I’m just going to start being me.’ But when I got there, I really didn’t know how to talk to people, I’d not interacted that much. I would just say really weird things. I started making friends by baking. And I’ve got a lot more normal as time’s gone on.” In her descriptions of the whole TV experience, there is a residue of this social anxiety – worrying that the other contestants would hate her, being astonished when they turned out to be really warm – but what her backstory illuminates is the intense sympathy she gives off, in person and on screen. People always say, on the internet, be kind, you never know what other people are going through; but it’s not often you meet someone who seems quite so alive to what other people might be going through.

The impact of her new stardom is subtle. Unlike some contestants, she hasn’t had photographers on her doorstep, possibly because it is quite hard to find, although she is recognised a lot – indeed, even if you had only seen the show once, you couldn’t mistake her for anyone else, so she has to look “put together” when she goes out, although I think her pure sunshine wardrobe predates her time on telly. Her extended family in Malaysia are incredibly excited. “My aunt Sandra keeps screenshotting the Daily Mail, and I really don’t want to know about the Daily Mail.” The show has evolved pastoral care: “Someone rings you every few days just to have a chat. And I think that carries on for quite a while. She called us throughout the whole show, and still calls now. I’ve not needed any support. But sometimes you can’t really tell with people, they surprise you.”

But Bake Off has left its mark. “I feel like I want to make the most of the opportunities, I don’t want to just sit back and chill the whole time. To have people like you for who you are is quite affirming, especially when you always worry about people not liking you.”

When you watch someone excelling at something – anything – while being so modest about it, they’re hard not to like. “I am modest,” she says, “but I think Rahul is more modest. If it came across the other way, it’s because I always expected things to go badly in the tent, not to be as good as it was at home, so if something went wrong in the tent, I didn’t really talk about it. Whereas Rahul expected everything to be perfect, because that’s how it was at home.”

She has just finished icing one star, having wiped off a previous attempt that already looked more or less perfect. “Can I have a break for a bit?” “Sure, a break from baking, or a break from me?” “From baking,” she says, and it was the wrong question and a diplomatically wrong answer, but it is fine, because I was leaving in a bit anyway, and I cannot help being high-energy and in your grill.

She gives me the turtle to take home. On the train – because I want to show it to people and also eat it – I lay it on my skirt to take a photo, and realise she has iced it exactly to match. It could be a coincidence, except my skirt is mad: lime green, black, white, coral. Hers is a delicate, unassuming kind of empathy; you don’t meet it every day.

Facebook Twitter Pinterest Kim-Joy’s turtle ginger biscuit. Photograph: Christopher Thomond/The Guardian

Kim-Joy’s ginger biscuits recipe

Prep 15 min

Cook 10-12 min (Plus decorating time – depends on how many biscuits you are decorating)

Makes About 12 medium-sized biscuits

For the biscuits

150g salted butter (or use unsalted and add salt to taste)

100g dark muscovado sugar

25g liquid molasses

2 tbsp beaten egg

1 tbsp ground ginger

¾ tbsp ground cinnamon

¼ tsp ground cloves

225g plain flour, plus extra to dust and roll out

For the royal icing

450g icing sugar

2 medium egg whites (or you can use 70g pasteurised egg whites if you are concerned about using raw egg whites)

Plus extra icing sugar and/or egg white to adjust – the consistency you are aiming for is one that returns to a smooth surface about 15 seconds after running a knife through it.

Food dyes

Preheat oven to 180C/fan 160C/gas mark 4.

Add the butter, sugar and molasses to a stand mixer bowl. Mix on high speed using the whisk attachment, until smooth and creamy.

Add the beaten egg, ginger, cinnamon and ground cloves. Mix until just combined.

Add the flour and combine using your hands until it forms a ball. Turn out on to a well-floured surface, and roll out to just less than the thickness of a £1 coin.

Use cutters to stamp out desired biscuit shapes, then transfer these shapes on to a baking tray lined with baking paper.

Chill for 10 minutes then bake for 10-12 minutes, or until the biscuits just start colouring at the edges. Leave to cool on wire rack.

Meanwhile, make the royal icing. I don’t really weigh my ingredients for royal icing so emphasis is on adjusting the quantities to get the right consistency. Use food dye to create different shades, and then transfer to piping bags ready for decorating later.

When the biscuits are cool, they are ready to decorate as desired.

To keep up-to-date with Kim-Joy’s recipes, you can follow her at @kimjoyskitchen on both Twitter and Instagram.