Ingredients:

• 5 eggs
• 150g sugar
• 5 ml vanilla extract (1 teaspoon)
• 420 g flour
• a pinch of salt
• 5 g baking powder (1 teaspoon)
• 250 ml milk
• 240 ml sunflower oil
• 2 tablespoons cocoa powder

Preparation:

1. Heat the oven to 150°C. Grease and flour a 9-inch round springform pan.
2. In the glass of a blender, place the eggs and sugar. Blend for about 1 minute.
3. Add the vanilla, flour, salt, baking powder, milk and sunflower oil to the blender. Blend until you obtain a homogeneous and perfectly integrated mixture, about 1 minute.
4. Remove half of the dough and place it in a container. Add the cocoa powder to the rest of the mass that was left in the blender and blend for a few seconds until integrated. Pour this chocolate mass into another container.
5. In the prepared pan, place 6 to 8 tablespoons of the vanilla batter in the center. Add 6 to 8 tablespoons of the chocolate batter into the center of the vanilla batter. Form concentric circles until you finish with both masses, reducing the number of tablespoons towards the end.
6. Bake for 50-60 minutes or until lightly golden around the edges, and a toothpick inserted into the center comes out clean. Remove from the oven, let cool in the mold for 10 minutes and then turn out onto a rack.