Cranberry Upside-Down Cake | Williams Sonoma

Ingredients

• 4 Tbs. (1/2 stick) unsalted butter
• 3/4 cup firmly packed brown sugar
• 3/4 lb. cranberries
• 1 1/2 cups all-purpose flour
• 2 tsp. baking powder
• 1/4 tsp. salt
• 8 Tbs. (1 stick) unsalted butter
• 1 cup granulated sugar
• 2 eggs, separated
• 1 tsp. vanilla extract
• 1/2 cup milk
• 1/8 tsp. cream of tartar
• 1 cup heavy cream
• 1/4 tsp. vanilla extract
• 1 Tbs. confectioners’ sugar