The humble coarse-thread drywall screw is built to fasten drywall to wood or light-gauge steel framing, but it’s also a low-cost and simple fastener for making wood-to-wood connections ...

Make a paper pattern for the size and shape you want. Screw small screw eyes at the seven edges of your drawing (spots indicated on photo at left).

You won't need to bore a pilot hole, because these screws have serrated threads toward the tip that cut away wood like a saw.