Raspberries have a cousin that tastes similar but is more potent in flavor: Thimbleberries (Rubus parviflorus). Some say these berries are more raspberry than raspberries. They also do not need a trellis and have no thorns!
Thimbleberries look similar to Maple tree seedlings but with softer and thinner leaves. Their berries look like a short and wide raspberry. Unlike raspberries, their thornless canes do not need support as they stay upright and can grow up to eight feet tall. Like raspberries and blackberries, their roots send up shoots that propagate themselves. Having tried their berries and enjoyed the taste, I decided to keep my eyes out for them in the woods to transplant a few into my food forest.
After locating a good size patch while on a walk through our property, I came back with a shovel and 5 gallon bucket to dig them up. This was while they were still dormant for the winter, so I had to guess that this was the same patch I had seen the previous summer. I picked around a dozen plants (leaving plenty for wildlife). They had roots that were intertwined as they were likely all propagations of just a couple plants in the patch. I planted them in a row on the edge of my food forest for easy picking. It is convenient to not have to trellis them, but I will still have to contain them from taking over the food forest as they get established and send up new shoots. Thimbleberries do not seem to be as tough as blackberries – more like your red raspberries as transplanting them was maybe only 50% successful. Part of this is I did not dig very deep into the dirt, thinking they would be tough. Months later, they still had not come out of dormancy. Visiting the source patch showed that the other thimbleberries had put on leaves from the old canes, so I assumed I had no success. After another several weeks, I noticed the thimbleberries sending up new shoots rather than leaves on the old canes.
I now have around 6 thimbleberries putting on canes! I may have to wait another year before a decent harvest, but now I have thimbleberries in my own food forest. Shortly after discovering this, I found a patch much closer to the house than the source patch that is even putting on berries. Thus we should have plenty of thimbleberries from now on. Having them in the food forest is also helpful for knowing when to visit the bigger patches.
Thimbleberries put on the most berries in full sun, but the source patch was in nearly full shade and seemed to be doing fine. I planted mine in my full sun food forest. No need to worry about thorns when harvesting.
The berries themselves are similar in texture to raspberries except softer and juicy. Some can be seedy, but the seeds are very small like a fig. Apparently they only last a matter of hours, so ideally you eat them right from the patch or for a snack shortly after. This is why you will not find them in grocery stores. They melt in your mouth.
Wanting to grow these but do not have access to a wild patch to transplant from? Run a search for thimbleberry plants and seeds, and you should find some sources such as this one (not an affiliate link, just one I found). Make sure the latin name is Rubus parviflorus. Follow the instructions and enjoy!