Homemade Ice Cream Sandwiches

In a mixing bowl, combine cake mix, shortening, butter, egg, water and vanilla; beat until blended. Divide into four equal parts. Between waxed paper, roll one part into a 10x6" rectangle. Remove one piece of waxed paper and flip dough onto an ungreased baking sheet. Score dough into eight pieces, 3x2 1/2". Repeat with remaining dough. Bake at 350 degrees for 8-10 min. or until puffed. Immediately cut along the scored lines and prick holes in each piece with a fork; cool on baking sheets. Cut ice cream into 16 slices, each 3x2 1/2". Place ice cream between two chocolate cookies; wrap in plastic wrap. Freeze on baking sheet overnight. Store in airtight container.