SISTERS Lucy and Jane Batham have a lot to thank their grandmother's old ceramic mixing bowl for.

It was the bowl she used when teaching them to bake as children, and they're still using it today - producing thousands of brownies and other tray-bake treats each week for high-end retailers and online sales.

Eighteen months ago the sisters launched their company Tarte and Berry, initially baking from home. "For the first 12 months we worked from Jane's tiny flat, there were trays and trays of brownies, cake and caramel everywhere, lining the kitchen and living-room," says Lucy. "We were hauling 25kg bags of caster sugar up and down the stairs to the flat!"

When word spread about the business, which specialises in artisan bakery treats, the sisters invested in a bakery at Farsley, near Leeds. "It's a bigger space and allows us to produce 4,000 brownies a week, doubling the amount we made before. We could only make a batch of brownies at a time, yet we were getting bigger and bigger orders," says Lucy.

She and Jane combined their skills to set up their business. Jane trained at the Gordon Ramsay Tante Marie Culinary Academy then worked as a pastry chef in London restaurants and as a confectioner at Bettys in Harrogate, decorating cakes and patisserie.

After graduating from Leeds University, Lucy worked in PR and marketing, gaining experience in branding, product development and food retail.

"We wanted to do something together and create a bakery brand," says Lucy. "Over the past year we've built up a following, social media has played a huge part, I don’t think we’d be where we are without it. There's a big foodie scene in Leeds and people like checking out new pop-ups."

Tarte and Berry supplies to wholesalers across Yorkshire and to outlets such as Friends of Ham in Leeds and Ilkley, Fodder in Leeds and a coffee shop in Scarborough. A range of treats available online are sent out in beautifully wrapped parcels.

"There's something lovely about receiving a parcel of treats in the post," says Lucy, of Horsforth. "It's a bit different and makes a nice gift. Our bakes are bar-shaped so can be posted."

Their biggest range is the salted caramel brownie, and other brownie choices include peanut butter, chunky chocolate orange and peppermint. The tray bake range includes raspberry and almond Bakewell and lemon and blueberry drizzle. All the treats are made with fresh ingredients and have a gluten-free option.

Jane comes up with new ideas - and Lucy enjoys testing them. "Jane is cordon bleau trained and does all the baking, while I focus on promotion and sales. We work well together, mainly due to the fact that Jane loves baking and I have a sweet tooth!" smiles Lucy. "We're very honest with each other, we know what makes each other tick in a way that only siblings do. If I don't like a flavour I'll say so, and we'll work on it together."

The sisters regularly update their followers on Instagram with what's happening in their bakery, and they test products at food shows and hold pop-ups at festivals and venues such as Trinity Leeds.

Their hard work has paid off, with their treats earning them a BBC Good Food Show award, a Women in Business award, presented by entrepreneur Jacqueline Gold, and a Small Business award from BBC2's Dragons’ Den panelist Theo Paphitis. They're about to take on their first apprentice and some staff to help with events.

At the heart of their business is an old cream Mason Cash mixing bowl which Jane uses to mix toppings by hand. The bowl belonged to their grandmother who used it when bringing up their mum in the 1950s.

"Jane loved baking from a young age but our mum was a self-confessed terrible cook so my grandmother taught her, using this bowl," says Lucy. "When Jane was a teenager she gave her the bowl and she's taken it everywhere, including Surrey, where she trained at the Gordon Ramsey Academy, and London where she lived.

"People associate food, particularly baking, with family and memories - we always remember the cakes our grandmother made - and this bowl means a lot to us."

Sadly, the sisters’ mum died 10 years ago but they remain close to their grandmother, now 91. “She’s our biggest fan,” says Lucy. "We always take her a cake when we visit. She's very proud.”

While the name Tarte and Berry has a French patisserie feel, the sisters use Yorkshire produce. "We chose tarte because it's a lovely French word and we just played around with it from there," says Lucy. "People are really into artisan bakery now; they like to know where the food and ingredients are from.

"We use free range eggs, butter and fresh fruit from local suppliers. Our recipes are seasonal; at this time of year we use fresh summer fruits such as berries. The strawberry season is approaching and we use a strawberry farm in Pudsey.”

Adds Lucy: "It's hard work but it's a dream job. We love what we do, and we love working together."

* Visit tarteandberry.com, email hello@tarteandberry.com, Tel. 0777 2077602.