If you can't do what you want without burying everything there with several inches of soil then no, there isn't a way. If you use a coarse, well-aerated mix maybe the larger plants, too big to lift will put up with it. It depends on what kind they are, I probably wouldn't try this with heath family shrubs like rhododendrons and pieris for instance.

Agree 100% with the above. Planting most things too deeply is a surefire method of killing them and that's exactly what you will be doing by piling on more soil without lifting the plants. Is there a compelling reason for raising the soil level? If attempting to improve drainage, then I'd go to the trouble of lifting everything, as most plants will benefit from the improvement. If just for aesthetics, then I'd rethink the process in favor of some other solution.

I think it's part of the cycle of gardening to go down one path and later wish you'd done it different.

I agree with the other posters that most plants would suffer from another 2-3 inches of soil at their base. I have heard that palm trees actually like soil piled at their base - they have "opportunistic roots".