This activity is so much fun, kids love it and adults too! You'll need heavy whipping cream and a mason jar.
Make sure your whipping cream is very cold, fill a mason jar half way with the cream, screw on the lid and shake shake shake!
My family takes turns shaking the jar and passing it around the room.
After shaking the jar for a bit it should start to look creamy like the first photo.
Keep shaking and it'll start to separate like the second photo.
Keep on shaking until nothing is moving around in the jar anymore. Remove the butter and store in fridge.