The pattern is The World's Simplest Mittens by Tin Can Knits. It is a free download. Yay! I added the stripes myself because I wanted some interest and not a boring solid black mitten. I used Paton's Classic Wool in colors black and white and I used sizes US 6 and 8 needles.
I love these. They were super easy to make (hence the name) and knit up pretty quickly. Check mittens off my list of winter accessories to knit.