FIG. 1 is a perspective view of the collapsible measuring cup, showing my new design; FIG. 2 is a front view of the collapsible measuring cup, the back view being a mirror-image; FIG. 3 is a top view of the collapsible measuring cup; FIG. 4 is a bottom view of the collapsible measuring cup; FIG. 5 is a right side view of the collapsible measuring cup; and, FIG. 6 is a left side view of the collapsible measuring cup.