Place your rack in the center of the 350 degree oven. Place 11 large sized paper liners in a large sized cupcake pan. Set the pans aside.
Prepare the cupcake batter; Place the cake mix, coconut milk, oil, eggs, and flavoring in a large mixing bowl. Blend with an electric mixer on low speed for 30 seconds. Stop the machine and scrape down the sides of the bowl with a rubber spatula.
Increase the mixer speed to medium and beat 2 minutes more, scraping sides again. The batter should be blended well. Fill each cup 2/3's full of batter and place the pan in the preheated oven.
Bake the cupcakes until lightly golden,nicely domed and spring back when pressed lightly with your finger about 18 to 20 minutes. When done remove from oven and let them cool 5 minute and then transfer to a cooled cookie sheet for cooling and frosting.
Frosting-Combine the sugar, sour cream and thawed coconut in a medium bowl. Let the mixture rest in the refrigerator 1 hour to dissolve the sugar, stirring occasionally. Frost your cooled cupcakes and place them in the refrigerator 2 hours. Leftovers can go into a rubbermaid container with a lid.