Preheat oven to 350 degrees F. Line a muffin tin with cupcake liners.
Combine the cake flour, baking powder, baking soda, and salt in a bowl. Stir to combine. Set aside.
Using a mixer, beat the butter and sugar on medium high until fluffy, smooth, and creamy. Scrape the sides of the bowl and add the egg whites. Beat until well combined.
Add the sour cream, vanilla, and coconut extract. Beat until combined. It may look curdled but scrape the bowl.
Slowly add the dry ingredients, followed by the coconut milk on low speed.
Beat on low speed until just combined and then add the coconut.
Stir by hand to maker sure there are no lumps — batter will be thick.
Fill the muffin liners about 2/3 full.
Bake for 15-20 minutes until tops are golden and a toothpick inserted in the center comes out clean.
Let cool completely before frosting.
To make the frosting, put the frosting in a food processor and pulse until powdered.
Add the butter and half the sugar in a mixer and beat on low until combined.
Add the rest of the sugar, salt, strawberry powder, and vanilla. Beat on high speed until thick and fluffy.
Add milk, one tablespoon at a time, until you have a spreadable consistency.
When the cupcakes are completely cool, frost.
Garnish with fresh strawberries and coconut if desired.