Upside-Down Citrus Cake Recipe | Valerie Bertinelli | Food Network

Ingredients

• 4 tablespoons unsalted butter, plus more for the pan
• 1 small to medium grapefruit
• 1 navel orange
• 1 Cara Cara or blood orange
• 1/2 cup granulated sugar
• 1/4 cup light brown sugar
• 1 tablespoon orange liqueur, optional
• 1 3/4 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1 stick (8 tablespoons) unsalted butter, softened
• 1 cup granulated sugar
• 2 large eggs
• 1 teaspoon pure vanilla extract
• 1 cup buttermilk