Preheat oven at 180 C for 15 min. In a bowl take milk add vinegar keep aside for 5 min.
Now sieve 3 times plain flour, salt, cocoa powder and baking soda mix well.
Take a bowl, add sugar and oil whisk it after that add milk, essence and food color mix well.
Now add flour on batches. Mix all gently and make a smooth batter.
Line cup cake tray with muffins liners and pour the batter. Fill on one third part of cup.
Baked it for 15 to 20 min or check when toothpick inserted should come out clean.