Heat oven to 375°F. To segment the grapefruit, slice off the top and bottom to expose the flesh. Stand the fruit on a flat end. Using a sharp knife to follow the curves of the sides, cut off the peel down to the flesh. Holding the fruit over a bowl, cut the segments free of the membrane on each side. Drain segments well; pat dry with paper towel. Place 3 tablespoons of the butter in 9-inch round cake pan. Place in oven until melted. Tilt pan to coat all sides with butter. Stir brown sugar and flour into butter; spread evenly in bottom of pan. Arrange grapefruit segments over brown sugar. Sprinkle with dried cranberries. Set aside. In large bowl, beat remaining 1/2 cup butter and granulated sugar with electric mixer on medium speed until mixed. Add eggs, 1 at a time, beating well after each addition. Add flour, baking powder, baking soda and salt. Mix on low speed until moistened. Slowly add grapefruit juice. Beat on medium speed until creamy. Spread batter over grapefruit segments. Bake 30 minutes or until toothpick inserted in center comes out clean. Loosely lay sheet of foil over cake during last 10 minutes of baking to prevent over browning. Remove from oven; let stand 5 minutes. Place heatproof plate over pan. Carefully invert to unmold. Spoon any fruit or syrup in pan bottom over the cake. Cool 30 minutes. Serve warm or cool. Makes 1 cake (12 servings).