Super-quick sponge mixture
Beat the egg whites and salt until stiff using the whisk on a hand mixer. Gradually add the sugar and continue beating until the egg whites turn glossy. Whisk in the egg yolks. Sieve in the flour, carefully fold in with the carrots using a rubber spatula. Spread the sponge mixture into a rectangle (approx. 5 mm thick) on a baking tray lined with baking paper.
Bake for approx. 7 mins. in the centre of an oven preheated to 220°C. Sprinkle sugar onto a tea towel. Remove the sponge from the oven, tip out onto the towel, wipe the baking paper with a damp towel, carefully peel away the paper. Cover the sponge immediately with the upturned tray, leave to cool.
Stir the mascarpone, sugar and vanilla sugar until smooth, carefully fold in the whipped cream. Spread 3/4 of the cream over the sponge, arrange the mango on top, tightly roll up the roulade. Spread the remaining cream over the roulade.
Sprinkle the biscuit crumbs on top of the roulade