Beat the egg with the sugar and, separately, the cream with the mascarpone. Drizzle the extra virgin olive oil into the egg and sugar, beating as you go, and then add the cream and mascarpone. Lastly add the milk. Separately sift the flour with the baking powder and the cocoa, then beat them into the mixture. Line a rectangular baking tin with dampened greaseproof paper (this helps it to shape better). Pour the mixture into the baking tin and bake at 160°C for 45 minutes. Make sure the sponge cake is cooked by sticking a wooden toothpick into it; if the toothpick comes out clean, the cake is ready. In the meantime toast the flaked almonds on a high heat. Decorate the sponge cake with the icing sugar and flaked almonds.