Melt butter in a saucepan then add the milk and stir over medium low heat until combined.
Microwave milk for 20 seconds in a glass measuring cup.
Slice the butter in 5 pieces in a microwavable bowl and microwave for 30 seconds, stir until all is melted.
In a mason jar, pour the milk in. Then using a handheld frother wand or immersion blender, pour the butter in and blend for 1 minute!
