Cook potatoes, then peel and grate them. Let cool completely. Beat eggs well until they become foamy. Add salt, black pepper, baking powder, and potatoes and mix well.
Heat oil in a non-stick pan until it is hot. Pour in the mix, flatten the surface with the back of a spoon, and place the lid on. Reduce heat and fry for about 10 minutes, until kookoo is cooked under. Cut radially into 4 equal pieces, turn over, and fry for another 10 minutes.