Chec- Quickly desert

The cake is a cake made from a composition obtained by simply mixing the ingredients (flour, butter, egg, sugar, baking powder), usually baked in a rectangular shape.
Ingredients:4 eggs, 180 g flour, 150 g sugar, 3 tablespoons mineral water, 1 sachet baking powder, 2 tablespoons oil, 2 tablespoons cocoa, 2 bags vanilla sugar, 100 gr crushed walnuts, 1 pinch of salt.