I’ve had a set of bench cookies for a while and just recently used them for the first time. I also had a set of risers and realized that called for a second set of cookies so I made a set of “cake squares”. I realized how helpful these would be for drilling and using the jig jaw on top of my bench. In a couple of one-hour sessions, a little shop fun was enjoyed. I used some 5/16-18 T-nuts (matches riser threads) in 3 in square 1/2” plywood, recessed so that a matching square of 3/4” plywood could be glued to the back. I checked out 3 different small remnants of rug gripper, the kind that looks like shelf liner or tool box liner and found that one had much more resistance to slip than the other two. I cut eight 3-1/2” squares, of the best gripper and took four of them and folded it twice before nipping off the corner to make a hole for the riser to thread into the cake square. I cut small pieces of masking tape to cover the threaded holes in the T-nuts and used spray glue only on the wood before applying the gripper. After sitting weighted down overnight, I trimmed the gripper surface to match the wood. Voila! – no bake cake squares that give 3-1/4” clearance.
-- Like Guy Clark sez - "Sometimes I use my head, Sometimes I get a bigger hammer"