Sift the flour with the baking powder and powdered sugar. Add the oil and 1/2 cup water. Kneads dough. Breaks off a ball (the egg) and put in the freezer or refrigerator. With the remaining dough to cover bottom of pan (30-35 cm), slightly stealing side. Sweet mixed with vanilla and smeared equal layer. Top grate in large pieces chilled dough already. Bake at 180 C. The finished cake sprinkled with powdered sugar. You can also add walnuts.