We do have products with a return, in prefinished and unfinished. Depending on which side of your staircase is open, you will need a left or a right return tread.
Standing at the bottom of your staircase looking up, if the right side is open you need a right return tread. If the left side is open, you need a left return tread. If both sides are open, you need a double return tread.
To see the Butterscotch Traditional Left, Right, and Double Return Treads, see the links below.
Red Oak Butterscotch Traditional Left Return Stair Tread-
http://www.stair-treads.com/traditional-treads-and-risers/traditional-1in-stair-treads/left-return-traditional-treads.html?color=86
Red Oak Butterscotch Traditional Right Return Stair Tread-
http://www.stair-treads.com/traditional-treads-and-risers/traditional-1in-stair-treads/right-return-traditional-treads.html?color=86
Red Oak Butterscotch Traditional Double Return Stair Tread-
http://www.stair-treads.com/traditional-treads-and-risers/traditional-1in-stair-treads/double-return-stair-treads.html?color=86