Caramelized Pecan Upside-Down Cake

Ingredients

• 4 large eggs, separated
• 1/2 cup packed brown sugar
• 1/3 cup butter, melted
• 1 teaspoon ground cinnamon
• 1 cup chopped pecans
• 1 cup sugar
• 1/3 cup 2% milk
• 1 teaspoon vanilla extract
• 1 cup all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon salt
• 1/4 teaspoon cream of tartar
• Sweetened whipped cream, optional