Preheat oven to 350 and place cupcake liners in muffin tins.
Sift cake mix into a medium bowl and set aside. In a larger bowl mix together eggs, oil, greek yogurt (or sour cream), vanilla, coconut, and milk. Mix in cake mix until smooth. Fill each liner 3/4 full. Bake 15-20 minutes until an inserted toothpick comes out clean.
For the frosting, beat butter until very light and fluffy (about 2 minutes). Mix in cocoa powder, coconut, and 3 tablespoons heavy cream, mix until smooth. Mix in 3 cups powdered sugar. Add additional cream and/or powdered sugar until desired consistency is reached (*for piping you will want to double the frosting recipe and look for a slightly stiffer consistency). Sprinkle with toasted coconut flakes if desired. Store in airtight container at room temperature up to 3-4 days. Enjoy!
Notes
Store in airtight container at room temperature up to three days.