Preheat the oven to 350°F. Line 24 standard muffin tins with double cupcake liners.
Separate egg yolks from egg whites. (It’s easiest to separate them while cold.) Let egg whites sit at room temperature while preparing the batter so they whip properly.
Melt the chocolate in ½ cup boiling water, stirring until smooth. Set aside to cool slightly.
In a medium bowl, sift together the cake flour, salt, and baking soda.
In a large mixing bowl, cream butter and sugar together until light and fluffy, about 3–4 minutes.
Add egg yolks one at a time, beating well after each addition.
Mix in the melted chocolate and vanilla until fully incorporated.
Add the flour mixture alternately with the buttermilk, beginning and ending with flour. Mix just until smooth. Do not overmix.
In a clean bowl, beat egg whites until stiff peaks form.
Gently fold the whipped egg whites into the batter in two additions, folding just until incorporated.
Fill cupcake liners about ¾ full.
Bake for 20–30 minutes, checking at 15 minutes. A toothpick inserted into the center should come out with a few moist crumbs attached.
Cool cupcakes 5 minutes in the pan, then transfer to a wire rack to cool completely before filling.
To Prepare the Coconut Pecan Frosting:
In a medium saucepan, combine evaporated milk, sugar, egg yolks, butter, and vanilla.
Cook over medium heat, stirring constantly, until thickened, about 12 minutes. The mixture should coat the back of a spoon.
Transfer to a large heatproof bowl.
Stir in coconut and pecans.
Let cool, stirring occasionally, until thickened and spreadable.
To Prepare the Ganache:
Place chopped chocolate in a heatproof bowl.
Heat whipping cream until just boiling (either on the stovetop over medium heat or in the microwave).
Pour hot cream over chocolate. Let sit 1–2 minutes, then whisk gently until smooth.
Add butter and whisk just until glossy and smooth. Do not over-whisk.
Let cool until thick enough to scoop.
To Assemble:
Using a small knife, cut a shallow cone-shaped piece from the center of each cupcake.
Fill each cavity with ganache.
Spoon coconut pecan frosting generously over the top.
Notes
Storage: Refrigerate for up to 3 days. Bring to room temperature before serving.
Double Liners: Prevent sticking and help structure.
Frosting: Makes a generous amount. Use less if desired.