I found this website with a recipe for rhubarb muffins that looked good. (meghantelpner.com)
Made this recipe this weekend, but tweaked to make a cross between this and your strawberry rhubarb muffins (as well as a little less sugar). (paleomg.com)
I have to add baking rhubarb muffins to my daily routine now... or at least to my summer routine! (meghantelpner.com)