The ingredients are given for the cake 16 cm in diameter, so if the shape is larger, feel free to increase the number of ingredients, at least 1.5 times, and then 2.
Mix the kefir, egg, sugar and soda. You can use a spatula, but for speed it is better to use a mixer.
Add flour and cocoa.
If you don't want cocoa, replace it with just flour.
Stir until smooth (with a mixer in a small aborato will be faster).
Put it in the form.
Bake at 180C for 20-25 minutes.
You can eat right away.
You can pour jam on top.
I also whipped up a few strawberries with cranberries, watered the cake and decorated with berries.
Or you can make a cake. Don't deny yourself anything.