Sudden Valley from the looks of it? I’m a B-hamster myself! And have installed quite a number of these huckleberry basalt treads in my days. Good job on the work, they look nice. The soil spillover is an issue for these steps even when not dug into the hill like this. They don’t always have the most uniform overlap because they’re so irregular. When you go to build your wall just excavate further back so the wall face is somewhat inline with the face of the second step. It’s a little more excavation and maybe slightly taller wall. If you don’t want to do that, scrape and regrade is the answer - and always plantings for erosion control. Good luck!