Oil a 4″ (10 cm) deep and 8 3/4″ (22 cm) in diameter form. Make a circle on baking paper that fits along the bottom of the form, cut it out and place it there. Next, flour the walls of the form. Sift the remaining flour well with the baking powder.
Pour in the flour in a thin trickle, while stirring nonstop. Once you get a homogeneous mixture, pour a little of it into a separate bowl and color it with the cocoa.
Then, begin pouring in the 2 mixtures a little at a time into the center of the cake form, alternating between them. Once you're out of cake mixtures, put the form in a preheated 338°F (170 °C) oven and bake about 75 min. or until your toothpick comes out dry when you poke the cake.
Finally, invert the baked cake carefully onto a flat surface.