Leave the eggs at room temperature. Beat them continuously in a bowl with a mixer or whisk until they turn into a fluffy cream.
Gradually add the sugar and beat once again. To the mixture, add the oil and stir again. Sift the flour, add 1 tsp baking powder and 1 vanilla to flavor it.
Add the baking soda to the yoghurt and stir. Leave it to activate. Then, add it to the bowl with the egg mixture.
Gradually pour in the flour to the mixture and continue beating so that all ingredients are mixed. Set aside 1 cup of the cake mixture and pour 1 tbsp cocoa and 1/2 tsp cinnamon to it.
Smear a cake form with oil and sprinkle it with flour. Pour in the light mixture. Then, evenly distribute the brown mixture on top. Put the cake to bake in a preheated 356°F (180 °C) oven until ready.
Check with a toothpick to see if it's baked enough. After it is, invert it onto a plate. Mix the powdered sugar with 1 tbsp cinnamon and sprinkle it over the cake through a sieve.