Preheat oven to 350F. Line 28 cupcake tins with liners. You can bake in 2 batches if you don’t have enough tins.
Whisk together the all-purpose flour, coconut flour, baking powder and salt in a medium bowl; set aside.
Using a hand mixer or stand mixer fitted with the paddle attachment beat together the butter and sugar on medium-high speed until thick and lighter in color, 2-3 minutes. Add the eggs one at a time, beating well after each addition. Scrape down the sides of the bowl between each addition.
Alternately add flour and coconut milk in three additions on low speed beginning and ending with flour, scraping down the sides of the bowl as needed. Add the next addition when your batter is streaky; if you wait too long, you will overmix by the time you’ve added the remaining ingredients. You want to stop mixing as soon as the last flour has disappeared. I like to fold in the last addition of flour with a spatula to avoid over beating.
Scoop or pour the batter into the liners ¾ full. I use a large cookie scoop for this task and it works beautifully. Sprinkle some toasted coconut on each cupcake. Bake in preheated oven for 15-20 minutes. I always start checking at 12 because I’m not a fan of dry baked goods. The cupcakes are done when a toothpick, inserted into the center, comes out with a few clinging crumbs but no wet smears!
Remove from tins immediately and let cool on a wire rack. They must be completely cool before filling and frosting.
Cut a hole in the top of each cupcake with a pairing knife and fill each with about 2 teaspoons of curd. I don’t measure, I just fill up the darn hole. It doesn’t matter. The more the merrier. And, no, those little bits of cake don’t go to waste. Those have my husband’s name on them.
Fit a piping bag with your favorite tip (I used an Ateco 883 here), fill with frosting and pipe on the desired amount of buttercream. In my opinion more is not more as with the lemon curd.
Sprinkle with more toasted coconut. Best if served the day they are made.