Position a rack in the middle of the oven and pre-heat to 350° F (180 C).
Line 12 standard muffin cups with paper liners, or grease with butter and dust with flour.
In a bowl, sift together the flour, baking powder, and salt.
In the bowl of a mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light, 2-3 minutes.
Add the eggs, one at a time, beating after each addition.
Add the vanilla and beat until well combined.
Beat in the 1 cup coconut.
Add half of the flour mixture and beat on low speed until combined.
Continuing to beat on low speed, add the buttermilk, and then add the remaining flour mixture.
Divide the batter among the prepared muffin cups, filling them about three-fourths full. (You may have a little batter left over, for baking additional cupcakes).
Bake until lightly golden and a toothpick inserted into the center of a cupcake comes out clean, about 18 minutes.
Let cool in the pan on a wire rack for 5 minutes and then transfer the cupcakes to the rack and let cool completely, about 1 hour.
Using a paring knife, create a hollow about 1 1/2 inches in diameter and 1 inch deep in the center of each cupcake.
Fill each hollow with a spoonful of the lemon curd.
Spread the filled cupcakes with a thick layer of the frosting (or pipe it on with a piping bag).
Sprinkle with the remaining 1 cup toasted coconut.*
*To toast coconut, spread it in an even layer on a baking sheet and bake at 325 F, stirring occasionally, until lightly golden, 5 - 10 minutes.