In a large bowl, mix together the oats and shredded coconut. Set the mixture aside.
In a saucepan over medium heat, combine the butter, milk, cocoa powder, and sugar. Stir occasionally until the mixture comes to a boil.
Once boiling, continue stirring and let the mixture boil for 4 minutes. This helps the macaroons set properly.
Remove from heat and immediately stir in the oats and coconut, mixing until everything is well coated.
Using a spoon or a cookie scoop, drop portions onto a parchment-lined baking sheet.
Let them cool completely at room temperature before serving (about 1 hour or until firm). Once set, the chocolate coconut macaroons should lift easily from the parchment paper without sticking.