The pattern is Kwik Sew 3730, which I also used to make Marcus' flannelette jumpsuit that I keep dressing him in. I'm making another one up soon, but I wanted to make this little shirt first.
Fabric is from Spotlight, bought on an expedition with my mum, niece and nephew (and baby Marcus of course!). I have enough left over to make him a long sleeve shirt for mid-winter too, so that's on the cards for next month.
Today the hunt begins for teeny green apple shaped buttons, and then the long sleeved shirt making begins.