Holding the blue lightsaber, it's Koko Black. And gripping the red, it's Black Star Pastry. The two sweet stars have combined forces to create a special meteor cake to celebrate World Chocolate Day on Wednesday, July 7.

Black Star's group pastry chef Arnaud Vodounou set out to create a light, gravity-defying mousse. "I tried to create a cake that is really dense in terms of chocolate flavour, however I didn't want a cake that was too heavy. So I tried to make the mousse as light as possible, especially because I have three layers of mousse on top of each other," Vodounou says.

Here's a meteoric rise up the layers from bottom to top: 100 per cent cocoa dark chocolate and almond financier; chocolate praline crunch made with bavarois, cocoa nibs and hazelnut praline; salted caramel dark chocolate layer using 70 per cent cocoa from Sao Tome; light muscovado sponge; dark chocolate mousse; light muscovado sponge; dark chocolate mousse; hazelnut praline cremeux (praline whipped with cream and milk); another layer of light muscovado sponge; and more dark chocolate mousse.

Then, says Vodounou, the "cherry on the cake" is a hazelnut praline truffle posing as a meteor, which is rolled in black cocoa powder and blitzed charcoal cocoa nibs, skidding to a halt with a "chocolate flame" following behind in a blaze of chocolate glory.

As well as Koko Black's popular praline truffle, the layer cake features its 70 per cent cocoa Sao Thome single origin chocolate. Vodounou describes the dark chocolate, sourced from central African island Sao Tome located on the equator, as floral, with not too much acidity.

"The challenge that I had is the sugar content. I didn't want something that was too sweet, and by using [hazelnut] praline, which is 50 per cent sugar, it wasn't easy, but I think we've got a beautiful version that highlights the best of both worlds."

The meteor cake collaboration crashes into selected stores next Wednesday for one day only, priced at $15 per portion.

It will be available for socially-distanced pick up from Koko Black at The Strand in Sydney, and Black Star outlets in Newtown and Rosebery.

In Melbourne, the limited edition layer cake will be sold at all Koko Black stores, aside from its Queen Victoria Market location.

Sydney chocoholics in need of a hump day lockdown treat next week can order a larger version of the cake for delivery on Wednesday ($55, serves four). Pre-orders open from 10am Friday at blackstarpastry.com.au. May the force be with you.