This doughnut is a two-tone dessert which is perfect for the whole family. It is suitable both as something special to have at breakfast, or as something to round off a family meal. It does not end there: it has a very unusual two-colour effect which will entertain your children no end. You can enjoy yourself too, making the marbling effect in more or less the way you want your cake to look. You can prepare it in a ring mould as we did, or in a cake tin, square or rectangular. Furthermore, in this latter case the two-tone effect will come out in an interesting way. You will discover that, even if the recipe is always the same, the visual effects that you can get vary from one occasion to the next.
Get an electric whisk, or a food processor or mixer such as the Thermomix. Beat the eggs with the sugar. Add the milk and oil continue to beat well. Then add the flour and baking powder. Mix together well. Grease and lightly flour a mould shaped like a doughnut. Pour most of the mixture into the pan. Keep about one-third to one side to which you add the cocoa powder. When the cocoa is powder is well mixed in, pour the mixture over the rest of the dough without chocolate. Bake for 48 minutes at 180°C.