Set to open next month, the 55sq ft Longboys ‘to-go’ site will have a black exterior with bi-folding doors, with the interior featuring pops of brand's signature navy blue and neon pink colours.
The glass display cabinet and menu board will showcase a range of Longboys' brioche finger doughnuts, which are filled with home-made compotes and come with a variety of glazes and toppings.
Doughnut choices will change seasonally, with popular choices including a triple-chocolate brownie doughnut; strawberry and white chocolate; and lemon meringue pie.
A range of vegan and nut-free options are also available including a coconut chocolate doughnut.
Longboys was founded last year by former Hakkasan group pastry chef Graham Hornigold, and former executive pastry chef at the Mandarin Oriental hotel Heather Kaniuk.
As well as a dedicated outlet at Boxpark Wembley, the brand also has concessions within both Harrods and Selfridges in London.
"We’re so excited for King’s Cross to open," say Hornigold and Kaniuk.
"It has been a long time coming as lockdown put our plans back slightly, but we are delighted we can now move forward.
"We’ve always loved the area and we’re looking forward to working with the team at King’s Cross and be surrounded by a fantastic group of peers."