Heat the oven to 356°F (180 °C), butter a cake form and flour it lightly. You can also just use a regular tray with a 9″ (23 cm) diameter and put baking paper in it to prevent sticking.
While stirring nonstop, add the liquid to the dry products and mix until homogenous. Finally, pour the oil into the mixture and stir with a rubber spatula until you're sure that everything has mixed well.
Pour the cake mixture into a prepared form. Bake the cake about 40-45 min. Once ready, it should puff back up when you press it lightly in the middle with your finger. Take the cake out and leave it to cool completely.
For the chocolate glaze, mix the cocoa and sugar in a container on the stove and pour in the water. Heat on a moderate stove, while stirring constantly until the sugar melts.
Using a skewer, make holes in the cake and pour the chocolate sauce over it. Don't take the cake out of the form before the sauce gets absorbed. Leave it to cool for at least 30 min. before serving.