Pineapple Cake

¼ cup butter                                                
1 cup sugar                                                  
1 egg                                                            
¾ cup milk                                                   
3 tsp baking powder                                    
½ tsp salt                                                      
½ cup pineapple                                            
1-1/2 cup flour

SAUCE:
¾ cup sugar
2 Tbs cornstarch
1 cup boiling water
1 tsp butter
½ cup pineapple
(add butter then pineapple)

Bake in moderate oven for 30 minutes.