Mix the flour and baking powder together and set aside. Whip butter and 3/4 cup sugar until fluffy. Now add 1/2 tsp vanilla essence and the eggs and beat well.
Add little by little flour to the egg and butter mixture until it is well incorporated. Pre-heat the oven at 350F and grease the 9X13 baking sheet pan with butter and dust it with flour.
Now pour the cake batter on to the sheet pan and bake it for 30 minutes. Make sure you do not open the oven to check, even if you are tempted to. Insert tooth pick too check and see if it is done. The tooth pick should come out clean. Let the cake cool down completely.
In a mixing bowl, mix all three types of milk together which is condensed, evaporated and whole milk. Pierce the cake few places using a fork. Pour the milk over the cooled cake. It will take a few hours for the milk to be absorbed. I recommend, turn the cake after the milk has been soaked on one side so that the other side can be soaked properly.
Using the electric mixer, whip the heavy cream for 5-7 minutes. Then add powdered sugar and remaining 1 tsp of vanilla essence to it. whip for additional few minutes until it has thickened.
Spread it on to the cake and garnish with raspberries or strawberries or you can leave it like that with a dusting of cinnamon powder.
Keep it refrigerated. Serve chilled. You will love this super moist cake which I fell in love with when I tried for the first time.