Coconut cupcakes with Coconut Buttercream

I've been wanting to master the coconut cupcake forever and now I can finally take it off the list. These are not only some of the best cupcakes I've ever made, but they are also just one of the best things I've ever baked. They were so moist and soft, and the coconut flavor shined through perfectly. The buttercream was insanely fluffy, it was hard not to just eat it off a spoon.

Coconut Cupcakes with Coconut Buttercream
Adapted from: Cooking Classy
Yield: 40 cupcakes

Cupcakes
1 1/2 cups cake flour
1 1/2 cups all purpose flour
1 Tbsp baking powder
1/2 tsp salt

6 large eggs, at room temperature, yolks and whites separated
1/8 tsp cream of tartar

2 cups (396g) granulated sugar
3/4 cup unsalted butter, at room temperature
1/4 cup canola oil

1/2 tablespoon coconut extract
1 teaspoon vanilla extract
1 1/4 cups well shaken canned coconut milk, at room temperature


Directions
Preheat the oven to 350º F. Line muffin tins with cupcake liners and set aside.

Sift cake and all purpose flour into a large mixing bowl, then add baking powder and salt and whisk mixture for 30 seconds or until thoroughly combined. 

In the bowl of an electric stand mixer, fitted with the whisk attachment, whip 6 egg whites with cream of tartar on medium-high speed until stiff (but not dry) peaks form. Transfer to another bowl and set aside.

In the same bowl of the electric stand mixer, fitted with the paddle attachment, blend together granulated sugar, butter and canola oil on medium speed until well combined. Add in only 2 egg yolks, one at a time, and mix until combined after each addition. Then mix in coconut and vanilla extracts. 

Working in three separate batches, beginning and ending with flour mixture, begin by adding 1/3 of the flour mixture. Mix until combined and then add half of the coconut milk and mixing just until combined. Repeat process.  Scrape the sides of the bowl occasionally to fully mix everything.

Using a rubber spatula, carefully fold 1/3 of the egg whites into cake batter at a time and fold just combined after each addition (don't over-mix and deflate egg whites). 

Divide batter among cupcake liners, filling only 2/3 full (they will rise). Bake only 15-16 minutes. You will notice the tops may still look wet or underdone but if you insert a toothpick into the center of cake, it comes out clean. Allow to cool in pan 10 minutes then remove from pans and cool completely before frosting.

Coconut Buttercream
Yield: frosts 36 cupcakes

2 cups (4 sticks) butter, softened
4 cups powdered sugar
2 tablespoons coconut milk
2 teaspoons coconut extract
shredded coconut, for top of cupcakes

Directions
In the bowl of an electric mixer fitted with the paddle attachment, whip butter for 8 minutes on medium speed (I use "4" on my KitchenAid). Butter will become very pale & creamy.
Add remaining 3 ingredients and mix on low speed for 1 minute, then on medium speed for 5 minutes. Frosting will be very light, creamy and fluffy. Pipes the best if you use it right away.