Eggless marble cake

In my quest for the prefect Eggless Cake recipe, there is yet another, not quite successful attempt. Someday, I will get that perfect recipe.

1/4 cup maida
2 tbsp coco powder
1/2 cup sugar
1/8 cup cooking oil
1 tsp baking powder
1 tsp vinegar
1/2 cup water
a pinch of salt
1/2 tsp vanilla essence

Mix the maida and baking powder and sieve them to ensure even mixing.Keep aside.
Mix water,sugar,salt and make sure the sugar gets dissolved and then add vineger, oil and vanilla essence and mix well.
Add the sifted flour and mix well.
Keep aside half the mixture, and mix the cocoa powder with the rest.
On a greased baking pan, put blobs of vanilla batter, and intersperse with blobs of chocolate batter. Place vanilla batter over chocolate, and chocolate over vanilla. Draw patterns with a knife (I made more chocolate batter, so it didn't come out looking too good).
Bake in microwave for 4 minutes.