Before you cook anything, assemble your ingredients and prep your work station. Line a section of your counter with wax paper or aluminum foil to drop cookies onto.
In a medium sauce pan, heat butter over medium heat.
Once the butter begins to melt, mix in sugar, cocoa powder, and milk. Stir to combine.
As soon as the butter mixture starts to boil, boil for exactly 1 minute, stirring constantly.
After 1 minute of boiling, remove the pan from heat and stir in peanut butter, GF oats, vanilla, and shredded coconut (if using).
Using two spoons or a cookie scoop, drop cookies onto wax paper or aluminum foil. Allow the cookies to cool and harden before serving.