Pineapple Upside Down Cake

1/2 cup butter
1 cup brown sugar
8 slices canned pineapple
3 eggs, separated
3/4 cup sugar
1/2 cup pineapple juice
1 cup flour
1 tsp. baking powder
pinch of salt

Melt butter in large size frying pan.  Add brown sugar, and mix.  Put pineapple slices in pan and let simmer for 10 minutes.  Beat egg yolks until lemon colored.  Add sugar slowly, and when beaten in thoroughly add pineapple juice.  Sift together flour, baking powder and salt and add to above mixture, mixing well.  Beat egg whites until stiff and fold carefully into cake batter.  Pour into frying pan over pineapple and bake at 350 degrees for 30 minutes or until nicely browned.  Turn out on large round tray or dish and serve with whipped cream when cool.