In a bowl, add milk, sugar, vanilla essence and oil. Mix it well till sugar dissolves.
Sift together the flour, baking powder, baking soda and salt in a separate bowl.
Start adding dry ingredients into wet ingredients and fold gently. There should be no lumps.
Add tutti-frutti and walnuts to the batter.
Add vinegar and set aside the mixture for 5 minutes.
Set muffin liners in muffin tray.
Fill each cavity upto ¾.
Preheat the Oven at 180 degree Celsius for 10 minutes.
Bake the muffins at 180 degree Celsius for 25 minutes or until toothpick comes out clean.
Let the muffins cool down and then serve.