The ornamental design for a cakeplate, as shown and described.
FIG. 1 is a top perspective view of a cake plate, showing my design.
FIG. 2 is a bottom perspective view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation thereof.
FIG. 6 is a right side elevation thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged view of an area labeled 9 in FIG. 1.
The dot-dash broken lines depict boundary lines which frame portions of the claimed design that are illustrated for enlargement and form no part of the claimed design.