Healthy Eggless Choco Lava Cake

INGREDIENTS 

wheat flour - 1 cup(125 gms) 
cocoa Powder- 2 tbsp
baking powder- 1-1/2 tsp 
baking soda -1/2 tsp
salt a pinch
powdered sugar -3/4 cup (75-80gms)
vanilla essence- 1tsp
pieces of dark Chocolate 
oil- 1/2 cup