firstly, in a large bowl take ½ cup oil, 1 cup sugar, 1 cup milk, 1 tsp vinegar and 1 tsp pineapple essence.
whisk and mix well making sure the sugar is dissolved completely.
now place a sieve and add 2 cup maida, 1 tsp baking powder, ¼ tsp baking soda and pinch salt.
sieve the flour to prevent from any lumps.
mix well using cut and fold method.
mix to a thick cake batter consistency without any lumps.
transfer the cake batter to the prepared cake tin.
pat gently to remove any air incorporated.
now bake in a preheated oven at 180 degree celcius for 45 minutes.
bake until the toothpick inserted comes out clean.
cool completely and slowly unmould the cake peeling off the butter paper.
finally, enjoy pineapple upside down cake cutting into slices.