Here in the UK hazel/cob nuts have been harvested for generations, going back to the early post-iceage settlers.
Ray Mears did a series of programs exploring the wild foods our ancestors may have hunted/gathered. In one episode he experimented with cooking cobnuts by burying them in a layer of sand of approx 1 inch and having a small hot fire above them. He described the cooking as transformative making them buttery and delicious, compared to the drying slightly astringent raw nuts. They were able to eat more of them at a sitting and enjoy them in quantity, and a batch that were cooked appeared to last months before spoiling, compared to weeks for raw green nuts.
Hazel is easy to propagate by layering. Take a young stem and bend it down to lay flat on the ground. Slit the soil with a spade and pop the stem into the slit so it is buried. You can make a simple tent peg type arrangement using another piece of hazel at a notched fork to hold the stem in place. Leave the leafy far end of the stem exposed so it keeps growing. Over a few months the stem will
root and you can cut it away from the parent plant.