Orange Upside-Down Cake(6 Servings)  
["4 oranges", "12 Tbsp. room-temperature butter", "1 c. brown sugar", "1 1/2 c. flour", "1 1/2 tsp. baking powder", "1/4 tsp. salt", "2/3 c. granulated sugar", "2 eggs", "1 tsp. vanilla", "1/2 c. milk"]
["Heat oven to 350\u00b0.", "Grate 1 tablespoon of colored zest from oranges.", "Peel oranges, cutting away all white pith right down to the flesh.", "Cut sections away from membrane.", "Melt 4 tablespoons butter and brown sugar in a 9-inch cake pan.", "Arrange orange sections in sugar.", "Combine flour, baking powder and salt.", "Beat remaining 8 tablespoons butter and granulated sugar until fluffy. Beat in zest, eggs and vanilla.", "Beat in half the flour, then milk and finally remaining flour.", "Spread over oranges.", "Bake until toothpick stuck in center comes out clean, 30 to 35 minutes.", "Cool 3 minutes; turn onto a platter.", "Leave 1 minute before removing pan."]
["oranges", "butter", "brown sugar", "flour", "baking powder", "salt", "granulated sugar", "eggs", "vanilla", "milk"]