Preheat the oven to 180 ° C and butter two circular baking pans (I used 24 cm diameter pans).
In the mixer bowl add the oil, yogurt, sour milk and sugar. Then add the eggs one by one.
Then add the flour slowly. Once homogenized add baking soda, baking powder, salt, and vanilla.
Add the mixture to the pans and bake at the low level of the oven for 40-50 minutes, depending on the oven. Before removing the cakes from the oven, make the test with the knife (pin the cake with a knife, if the knife is clean then the cake is fine).
Let the cakes cool for 5 minutes and then remove them and place them on a cooling rack in order to cool completely.
After cooling (it will take about 4-5 hours, depending on the temperature of the room), with the help of a knife, cut in the middle, horizontally the cake in order to create four layers.