Florida Grapefruit Upside-Down Cake - Fresh From Florida : Fresh From Florida

Ingredients

• 2 Florida grapefruit, peeled, seeded and segmented
• ½ cup Florida raw cane sugar or light brown sugar
• 2 tablespoons unsalted butter
• 1 teaspoon vanilla extract
• 1 cup whipped cream (store-bought or homemade)
• Fresh mint, for garnish (optional)
• 1 cake mix (store-bought or homemade)
• 1 cup Florida sugar
• 1 tablespoon Florida grapefruit zest
• 1½ cups unbleached all-purpose flour
• 1 teaspoon baking powder
• ¼ teaspoon salt
• 6 tablespoons unsalted butter, softened
• 2 large eggs
• ½ cup milk
• 2 teaspoons pure vanilla extract