Cake:

1 1/2 c. sifted all-purpose flour
1 3/4 tsp. baking powder
1/4 tsp. salt
1/3 c. butter
3/4 c. granulated sugar
2 eggs, separated
1 tsp. grated lemon zest
1 tbsp. fresh lemon juice
1 tsp. vanilla
1/2 c. sour cream

Topping:

1/3 c. butter
2/3 c. firmly packed brown sugar
1 (20 oz.) can pineapple, drained (2 tbsp. liquid reserved for cake)
10 maraschino cherries

Prepare Topping: Melt butter in 10-inch cast-iron skillet. Off heat, stir in brown sugar. Pat pineapple dry. Arrange in skillet. Place cherry in center of pineapple slices.

Prepare Cake: Heat oven to 350°F. Sift flour, baking powder and salt onto waxed paper; set aside. Beat butter with 1/2 cup sugar in large bowl at high speed until light and fluffy. At medium speed, beat in yolks, zest, juice and vanilla. Combine sour cream and reserved pineapple liquid in a small bowl. Add flour mixture to batter mixture alternately with sour cream mixture, beating after each addition only enough to blend. Using clean beaters, beat whites in a bowl until soft peaks form. Beat in 1/4 sugar, 1 tablespoon at a time, until stiff peaks form. Fold into batter; scrape into skillet.

Bake at 350°F for 35 minutes or until springy to the touch. Cool cake in skillet on rack for 10 minutes. Loosen edges; invert onto plate. Serve slightly warm.