Make your shallow cake pan deeper - If your 9-inch cake pan in less than 3 inches deep, make a paper collar to support the cake as it rises. Cut two 6 x 16 inch strips of parchment. Fold the two strips lengthwise to get two 3 x 16 inch strips. Butter one side of each strip. Line the inside edge of the pan with the strips, nestling them into each other, with the folded edge on the top and the buttered side facing in