Preheat oven to 350°. In a small bowl, mix brown sugar and butter; spread onto the bottom of a greased 13x9-in. baking pan. Top with pineapple slices. Place a whole cranberry in the center of each pineapple; sprinkle remaining cranberries around pineapple., For cake, in a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla. In another bowl, whisk flour, baking powder, salt, cinnamon and allspice; add to creamed mixture alternately with sour cream, beating well after each addition. Fold in cranberries; spoon over pineapple., Bake until a toothpick inserted in center comes out clean, 50-60 minutes. Cool 10 minutes; invert onto a serving plate. Serve warm; if desired, top with whipped cream.