Method:

1. Sieve maida twice and keep aside.Cream sugar and curd until sugar completely dissolves. Add baking powder, baking soda to the creamed mixture and mix well.
2. Leave aside for 5 mins and you can see the bubbles appearing. Now add vanilla essence,cooking oil and mix well.
3. Next slowly add maida in portions at a time and blend with wet ingredients. Beat well with a whisk until creamy and thick.Add choco chips and give a quick mix.
4. Preheat oven to 180 deg C for 10mins. Meanwhile lay the muffin liners in the muffin pan .Spoon the batter into each muffin liner till 3/4th of the liner.Top it with few more choco chips.Bake in preheated oven at the same temperature and bake it for 20-25 mins or till a fork inserted into the muffins comes out clean. Allow the muffins to cool down in wirerack and then store or enjoy it warm :)

My Notes:

• As my muffin liners were small I had to bake it in 2 batches, 6 in each batch so got 12 small muffins.My first batch puffed up evenmore...as I had to rest the batter till the first batch was done the second batch muffins didnt puff up so well when compared to the first batch. The pics shown in this post are from the 2nd batch.But tastewise no difference at all. But I suggest you to bake it as soon as the batter is prepared, dont let it rest.
• Use curd at room temperature.Do not try to reduce oil and curd, I tried once to reduce oil and the cake was a great flop ;) 
• Also after the batter is ready, dont allow the batter to sit for more than he preheating time as baking soda reacts faster. 
• Dont be skeptical in using curd, the taste of curd is totally not shown in the cake. You can use homemade curd or use nestle curd which is very thick and works good too.
• You can use icing sugar too, I used normal sugar only. I felt 3/4 cup of sugar was enough but the orginal recipe called for 1 cup. If you have a very sweet tooth then use 1 cup of sugar.
• This recipe yields 12 small muffins or 6 large muffins.