Place flour, baking powder, salt, sugar, butter, eggs, vanilla, and milk into mixing bowl. Beat slowly to moisten, then beat with an electric mixer at medium speed for about 2 minutes until smooth. Reserve 3/4 cup batter; pour the remainder into pan.

Add cocoa into the 3/4 cup reserved batter. Drop by spoonfuls over top of white batter. Using a knife, swirl the cocoa batter into the white batter to incorporate it in a marble effect

Take a kadai and add salt into in. Place a stand. And pre heat the kadai. Bake the cake 40- 45 minute,until an inserted wooden pick comes out clean