Preheat oven to 350 degrees. Spread coconut in an even layer on a rimmed baking sheet. Toast in preheated oven, tossing once about halfway through, until golden brown 5 - 8 minutes (keep a close eye on it because it will change color rapidly near the end. Leave oven at 350 to bake cupcakes). Allow to cool slightly then pour into a food processor and pulse until finely ground, about 1 minute.
Pour ground coconut into liquid measuring cup with buttermilk and stir to combine. Let rest 10 minutes.
Sift all-purpose flour and cake flour into a mixing bowl. Add baking powder, baking soda and salt and whisk for 20 seconds.
In the bowl of an electric stand mixer fitted with the paddle attachment, whip together butter and granulated sugar until pale and fluffy. Mix in eggs one at a time, adding in vanilla with second egg. With mixer set on low speed, add in 1/3 of the flour mixture and mix just until combined then mix in 1/2 of the buttermilk mixture and mix until combined then repeat process once more (scrape every bit of the buttermilk coconut mixture out with a rubber spatula) and finish by mixing in last 1/3 of the flour mixture. Fold in toasted pecans.
Divide batter among 12 paper lined muffin cups filling each about 2/3 full. Bake in preheated oven until toothpick inserted into center comes out clean, about 19 - 21 minutes. Cool in pan several minutes then transfer to a wire rack to cool completely. Once cool frost with cream frosting and sprinkle tops with toasted coconut and pecans. Store in an airtight container.
For the frosting:
In the bowl of an electric stand mixer fitted with the paddle attachment whip cream cheese and butter until smooth. Mix in vanilla, then stir in powdered sugar and mix until smooth and fluffy (if it seems slightly runny, chill then stir before piping or spreading. I like to freeze it in the mixing bowl 5 minutes the beat with the mixer again then freeze 5 more and beat).