Thorntons is venturing into desserts, cakes and biscuits as it bids to boost its presence in the supermarkets.

Just a week after warning that soaring cocoa costs could push up the price of its chocolate products, Thorntons has unveiled nine chilled desserts and cakes and four cookies to "leverage" its chocolate heritage in the own label-dominated categories.

Thorntons' award-­winning chocolatier Keith Hurdman oversaw the development of all the lines, which contain Thorntons chocolate and toffee.

"There's a physical limit to how much you can do in chocolates so we decided to move into adjacent categories," said group marketing manager Matt Smith. "We will continue to do so as long as chocolate and toffee has a role within the chosen category."

Smith predicted that Thorntons' products would appeal more to consumers than premium own-label ranges such as Sainsbury's Taste the Difference and Tesco Finest. "Our products will not feature the elitist, high-faluting language used by some of those ranges and we will benefit from having a brand synonymous with quality and authenticity," he said.

The desserts and cakes are made by Elisabeth the Chef and would be positioned as "above Cadbury and Nestlé desserts but more accessible than Gü".

The range comprises: four chilled mousses in chocolate and toffee flavours (rsp: 89p); Sticky Double Toffee Pudding (rsp: £1.99); Sticky Double Chocolate Pudding (rsp: £3.59); Sticky Toffee Cake (rsp: £5); Chocolate & Toffee Tart, and a Treacle Tart (rsp: £3.89 each). They hit chillers in retailers this month but will not be available in Thorntons' own outlets.

The cookie range, made by Northumbrian Fine Foods, is in Morrisons and Thorntons' own high street stores now. Selected SKUs will also reach Asda and Sainsbury's this month. The line-up consists of Triple Chocolate Chunk; Ginger & Dark Chocolate; Praline & Milk Chocolate; and Sicilian Lemon Meringue (rsp: £1.79).