Add the coconut to a large bowl or deep container. Blend on low with an immersion stick blender, moving it around and scraping the blades about once a minute, until the flakes become a fine, flour-like texture.
Keep blending and scraping until the coconut softens and turns slightly liquid (at least 10 minutes).
Move to a regular blender and blend for a few minutes until spreadable and a little grainy (blend longer for smoother butter). If it will not move, add 1-2 tablespoons melted coconut oil, or go back to the immersion blender.
Pour into a container with a tight lid (a mason jar is a good choice).
Notes
Prep/total time 15 minutes. Use at least 3 cups of shredded coconut for best results.