The ornamental design for the combined cake and ice cream dessert, as shown and described.
FIG. 1 is a front perspective view of a combined cake and ice cream dessert showing my new design of the present invention, the rear perspective view being identical;
FIG. 2 is a top view thereof;
FIG. 3 is a side elevational view thereof, the opposite side being identical; and,
FIG. 4 is a fragmented front perspective view thereof.
The broken lines are for illustrative purposes only and form no part of the claimed design.