• Preheat oven to 350°F (177°C).
• Prepare topping first: Pour 1/4 cup melted butter into a parchment-paper lined cake pan. 
• Sprinkle brown sugar evenly over butter.
• Arange about 6-7 pineapple slices and all the cherries on top of the brown sugar.
•  Place pan in the refrigerator for a few minutes as you prepare the cake batter. 

CAKE BATTER PREP

• Whisk the cake flour, baking powder, baking soda, and salt together. Set aside.
• Using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter on high speed until smooth and creamy, about 1 minute.

  Add the sugar and beat on high speed until creamed together, about 1 minute.

  On high speed, beat in the egg whites until combined, then beat in the sour cream and vanilla extract.

  Pour the dry ingredients into the wet ingredients.

  Turn the mixer onto low speed and as the mixer runs, slowly pour in the milk.

  Beat on low speed just until all of the ingredients are combined.

  Do not over-mix. The batter will be slightly thick.
• Remove topping from the refrigerator. Pour and spread cake batter evenly over topping.
• Bake for 45 minutes, tenting foil on top of the cake halfway through bake time to prevent the top from over-browning.

  Remember we're doing an upside-down cake!
• Remove cake from the oven and cool on a wire rack for just 20 minutes. 
• Gently place a cake stand or plate underneath your cake pan, and flip it over!
• Enjoy!