I made a cookie cutter out of some spruce wood and some metal that I bought for a dollar at a local computer recycling non-profit. I copied a real outlet cover. The push pins were a temporary fix to test the idea. I replaced the pins with screws.The cookie dough melted and spread if I cut it before baking it. I got the result that I wanted by baking the dough as one sheet, and then cutting out the cookies while the dough was still hot and soft. The cookies stuck in the cutter, so I drilled the holes so that I could push the cookies out with a chopstick. Still have to try that modification.
The steel is 0.012″ thick, or approximately 30 gauge mild steel. The steel was shielding from a gaming console, I think. The steel cuts easily with metal shears, unlike stainless which will fight you every inch of the way and dull your tools.
Dough collected where the steel overlaps, so I cut away the steel at an angle to reduce the overlap.