Youngberries are one of the many hybrid berries that have raspberry and blackberry in their parentage. These are not GM, the first ones were bred about 100 years ago.
These things taste amazing, much like a boysenberry, but are smaller and more productive. They have no thorns on the canes (botanically they are known as prickles) and are strong vigorous growers.
Days to maturity Thornless Youngberry (Rubus sp)
Seeds planted N/A grown from divisions
Flowered 25/10/2017 Day 0
Fruit Ripe 07/12/2017 Day 43
I have added this to a larger list of vegetable days to harvest from seed.