Combine pineapple (with juices), spinach, banana, vanilla extract, and non-dairy milk in a blender or food processor until well combined -- makes a green goop.
Mix remaining ingredients in a bowl . Then pour in spinach mixture, stirring to combine. If it looks dry, add another 2-4 tbsp non-dairy milk (I find some pineapple is juicer than others). I added 3 tbsp.
Spoon into a greased muffin pan and bake 15-20 minutes at 375F.