Difficulty: Medium (2/5)
As a passionate home baker with decades of experience perfecting family recipes, I can vouch for this Grandma's chocolate cake—it's reliably moist, richly flavorful, and a hit every time.
Crack the eggs, separating the whites from the yolks.
Place the yolks in a bowl with the powdered sugar. Whisk vigorously until the mixture lightens and forms a ribbon when lifted from the bowl.
Incorporate the cocoa powder while continuing to whisk.
Sift together the flour, potato starch, and baking powder, then gently fold them in using a wooden spoon.
Melt the butter over very low heat in a saucepan, then stir it into the batter.
Beat the egg whites to stiff peaks with the pinch of salt. Delicately fold them into the chocolate mixture to keep it airy.
Pour into a buttered and floured mold.
Bake in a preheated oven at 180°C (thermostat 6) for 40 minutes. Test doneness: a knife inserted should come out with just a light coating.
Cool completely before unmolding and dusting with icing sugar.
