To make the pineapple layer, add the butter and brown sugar in a small saucepan. 

Cook over medium low heat until the sugar is dissolved and mixture is bubbling, about 5 minutes.

Spread the mixture over the base of a 9 inch cake pan. 

Arrange the pineapple slices and cherries on top of brown sugar mixture. 

Halve 4 pineapple slices and arrange them around the sides of the pan. 

Refrigerate the pan while you make the cake. 

To make the cake, preheat oven to 350ºF. 

Separate the egg whites from the yolks. 

In a bowl combine the flour, baking powder and baking soda. 

In the bowl of a stand mixer fitted with the paddle attachment cream the butter. 

Add the sugar and beat until smooth.  

Add the egg yolks, sour cream and vanilla extract and beat to combine. 

Add the milk and beat until combined. 

Add the flour mixture and mix to combine.   

In a bowl, whisk the egg whites until stiff peaks form.  

Carefully fold in the egg whites, working in batches. Do not overmix. 

Pour the mixture into the prepared pan. 

   Bake for 45-50 minutes or until a toothpick, inserted in the middle comes out clean. 

   Let the cake cool in pan for 10 minutes.

   Cover pan tightly with a serving dish and invert so that the pineapple side is up.