In a mixer with the paddle attachment, combine the flour, baking powder, 350 g of the sugar, salt, and butter until well blended.
Set aside 150 gr of this mixture, and add the cinnamon, sunflower oil, and the remaining 50 g of sugar to the mix.
Add the eggs and milk to the remaining amount of the original mixture and stir for 5 minutes.
Pour half of the cinnamon mixture into a 27 cm baking ring.
On top of that add the egg-and-milk mixture, and then sprinkle the remaining cinnamon mixture on top as well.
Bake at 160°C for 25-30 minutes.
Just before baking the cake, you can sprinkle additional cinnamon and sugar on top. This simple addition will create a thin, lovely crust, adding extra crunch to every bite and making your cake even more enjoyable!