Simplicity Sew Simple 1639
I have made this pattern a few times but it is style I like and is comfortable. It is super easy and can be made in probably 1/2 hour.
The fabric was from stash. While it isn't a sweater knit it looks like it is. It is an acrylic knit backing and the sweater look is on top. It is a medium weight fabric and was easy to sew.