Preheat oven to 350 degrees F. Line standard muffin tins with paper liners.
In a medium bowl, whisk together the flour, baking powder and salt. Pulse the shredded coconut in a food processor until finely ground and whisk into the flour mixture; set aside.
With an electric mixer on medium-high speed, cream the butter and sugar together until pale and fluffy, about 3 minutes. Add the egg, egg white and vanilla extract and beat until completely combined, scraping down the sides of the bowl as needed. Reduce the mixer speed to low. Add the flour mixture in three batches, alternating with two additions of coconut milk, and beating until combined after each.
Divide the batter evenly between the lined cups. Bake until a toothpick inserted in the center comes out clean, 18 to 20 minutes. Remove from the oven, let cool in the pan for 10 minutes, then remove to a wire rack to cool completely.
Make the Frosting: Using the whisk attachment of a stand mixer, whip the butter on medium-high speed for 5 minutes, stopping to scrape the bowl once or twice. Reduce the speed to low and gradually add the powdered sugar. Once all of the powdered sugar is incorporated, increase the speed to medium-high and add the vanilla and coconut extracts, mixing until incorporated. Whip at medium-high speed until light and fluffy, about 2 minutes, scraping the bowl as needed.
Garnish the Cupcakes: Using an offset spatula, spread a mound of frosting on top of each cupcake and create a well in the center. Place the toasted coconut in a shallow bowl. Roll the sides of the cupcake in the toasted coconut, then top with a few Robin's Eggs malted milk balls. The cupcakes should be stored in an airtight container at room temperature for up to 3 days.
Notes
Equipment: Any standard 12-cup muffin pan will work for these cupcakes.
Coconut Milk: Be sure to purchase canned coconut milk and not cream of coconut.
Coconut Extract: This is readily available in most grocery stores in the baking aisle, but can also be purchased online.
Whoppers Robin Eggs: Most grocery stores and places like Target stock these around Easter, but you can also buy them online.
Toasted Coconut: To toast the coconut for topping the cupcakes, spread in an even layer on a baking sheet, and bake at 325 degrees F for 8 to 10 minutes, watching closely so it doesn't burn. Remove from the pan immediately.
Storing: Keep these coconut cupcakes ultra-fresh by storing them in an airtight container on the counter at room temperature for up to 3 days.
Freezing: Planning to freeze the cupcakes for later is a great way to make them in advance. Freeze cooled and un-frosted cupcakes in a freezer-safe gallon ziplock for up to 3 months.
Thawing cupcakes: When you are ready to serve frozen cupcakes, remove them from the freezer and allow the cupcakes to sit at room temperature to thaw (about 2 hours).
Make-Ahead: You can bake these cupcakes fresh, up to 2 days in advance, or bake and freeze the cupcakes up to 3 months in advance and follow the thawing instructions before frosting and serving.