Melt butter in a sauce pan. Add the brown sugar and stir until dissolved and bubbly. Carefully pour into the bottom of a 12" spring form cake pan. Arrange slices of pineapple and cherries on the top.
In a bowl mix together the oil,eggs and sugar and beat for 2-3 minutes till well mixed.
Add the vanilla essence and the lemon juice.
Mix the flour, baking powder and salt and add it to the above mixture.
Add the buttermilk and mix well with a light hand.
Pour batter in prepared cake pan and bake in a preheated oven at 175 degree centigrade for 45 minutes.The cake is ready when an inserted wooden skewer comes out clean or when the cake springs back when lightly touched.
Invert into a serving platter.Serve with whipped cream and enjoy!