Steps
- Preheat the oven to 350°F / 175°C. Pour ¼ cup of melted unsalted butter into an ungreased 9in / 23cm round cake pan, 2in / 5cm deep. Sprinkle with ½ cup of packed light brown sugar.
- Blot 10 canned pineapple rings and 15 maraschino cherries dry. Arrange most rings on the base; halve the rest around the sides. Fill gaps with cherries and refrigerate while mixing the batter.
- Whisk 1½ cups of cake flour, 1 teaspoon of baking powder, ¼ teaspoon of baking soda, and ½ teaspoon of salt.
- Beat ¼ cup plus 2 tablespoons of softened unsalted butter for 1 minute. Add ¾ cup of granulated sugar and beat for 2 minutes, until fluffy.
- Beat in 2 large room-temperature egg whites, then ⅓ cup of room-temperature full-fat sour cream and 1 teaspoon of vanilla extract.
- Add the dry mixture on low speed, slowly pouring in ¼ cup of room-temperature pineapple juice and 2 tablespoons of room-temperature whole milk. Mix just until combined.
- Spread over the fruit. Bake for 43-48 minutes, tenting with foil halfway through, until a toothpick has only a few moist crumbs.
- Cool in the pan on a rack for 20 minutes, then invert onto a plate. Cool completely before slicing.