Preheat oven to 350-degrees F. Lightly grease and flour your cake pan.
Sift together flour, baking powder, baking soda, and salt. Set aside.
In a blender, blend together pineapple juice, pineapple pieces, vanilla extract, butter, sugar and blend them to mix until smooth. pour in your mixing bowl.
Add in half the flour and mix till well combined. stir in the margarine then add in the rest of the flour mixture and mix gently to a heavy paste
Pour in the batter into the baking tin. Bake at 175 degrees C for 30 - 35 minutes, or until toothpick comes out clean.
Let cake cool in its pan on a cooling racks until cooled completely brfore removing from the baking tin.
Enjoy!
