The ornamental design for an extendingcookware handle, as shown and described.
FIG. 1 is a perspective view of the extending cookware handle;
FIG. 2 is a left side elevational view of the extending cookware handle, the opposite side of which is a mirror image;
FIG. 3 is a top plan view of the extending cookware handle;
FIG. 4 is a bottom plan view of the extending cookware handle.
FIG. 5 is a front elevational view of the extending cookware handle; and,
FIG. 6 is a rear elevational view of the extending cookware handle.
The dash-dot broken lines represent the bounds of the claim and all other broken lines illustrate unclaimed portions of the article. None of the broken lines form a part of the claimed design.