First (well, after I started the oven preheating at 350) I pulled out my 9X9 (or close to that anyway) pan and filled the bottom with 4 cups chopped (about 1/2 in squares) rhubarb. Then I added 2 tablespoons water and 1 cup Splenda over the top.
Next I used the crisp recipe my sister gave me, but with a couple substitutions. I mixed together 1/2 package of cake mix, 1/4 cup vanilla yogurt (to replace the butter), 1 tablespoon cinnamon, and 2 tablespoons Splenda. I made it into a crumble with my fork and then covered the rhubarb.
About a 1/2 hour of baking later I had quite a yummy dessert (and my apartment smelled amazing)! I added a little Haagen-Das Vanilla, Honey and Granola Frozen Yogurt.
I made this yesterday and sampled it today. I actually think I like it a little better chilled overnight so you might want to sample it both ways. Happy eating!