Lightly grease three 8-inch round cake pans with butter or nonstick spray. Line with parchment paper rounds and dust with cocoa powder.
Preheat oven to 350°F (175°C). Whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt in a large bowl.
In a separate bowl, whisk the eggs, buttermilk, oil, and vanilla until smooth. Add to dry ingredients and mix until smooth, then whisk in hot coffee.
Divide batter among pans and bake for 22-28 minutes. Cool in pans for 10-15 minutes, then transfer to wire racks.
Toast chopped pecans for 6-8 minutes and shredded coconut for 4-6 minutes at 325°F (165°C). Cool completely.
In a saucepan, whisk evaporated milk, sugar, and egg yolks until smooth. Add butter and cook over medium heat for 8-12 minutes until thickened. Remove from heat and stir in vanilla, salt, pecans, and coconut.
For ganache, pour hot cream over chopped chocolate and let sit for 3-4 minutes. Stir until smooth, then mix in butter, vanilla, and salt. Let cool until thickened.
Assemble cake layers, adding half of the cooled filling between layers. Repeat with second layer.
Apply a thin crumb coat of ganache, refrigerate for 20-30 minutes until set.
Add a thicker layer of ganache on the cake and smooth with a scraper. Chill again for 10-15 minutes.
Toss pecans and coconut with gold sanding sugar and apply to the lower edges of the cake. Decorate with pecan halves, chocolate curls, and gold dust.
Refrigerate cake for at least one hour before slicing.
Notes
Use high-quality ingredients for the best flavor. Ensure eggs and buttermilk are at room temperature for easier mixing. Allow layers to cool completely to prevent melting the ganache when assembling.