Lift the cake on its sheet of foil so that one of its long sides is parallel to the edge of your counter. (The cake will be rolled lengthwise.) Spread the cream evenly over the cake with a rubber spatula, up to 1 inch before reaching the long end farthest from you. (Some of the filling will move to that end as you roll.)
Begin rolling by flipping the edge of the cake nearest you over onto itself. Then, with the aid of the foil that extends on either side of the cake, roll the cake lengthwise until you reach the other end. With you hands, wrap some of the roil around the roll to assist you in rounding the shape as you work toward the other end of the cake (otherwise, the cake will stick to your hands).
Cut each end of the roll on the diagonal for eye appeal, and sprinkle a light coating of powdered sugar over it to disguise any cracks in the cake. Lift it onto a serving plate with the aid of a long, wide spatula or a baking sheet without sides. If desired, decorate top of roll with Glazed Raspberries.
To decorate the top of the roll, place the raspberries into a 3 quart bowl. Heat currant jelly just until it's almost melted, but not hot. Pour the jelly through a strainer over the berries (push it through the strainer with a rubber spatula.) Gently slide the rubber spatula under the berries, and fold the two together. Repeat this three more times. The object is to coat the berries evenly. Carefully scoop the raspberries on top of the cake, down the length of the roll.