1. Prepare the Cake Pans and Preheat:

• Preheat the oven to 350°F (175°C).
• Spray two 8-inch round baking pans with nonstick baking spray with flour. This ensures the cakes will release cleanly.

2. Combine Dry Ingredients:

• In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.

3. Combine Wet Ingredients:

• In a medium bowl, whisk together the eggs, vanilla extract, milk, and oil.

4. Combine Wet and Dry Ingredients:

• Add the egg mixture to the flour mixture and whisk well to combine.
• Scrape down the sides and bottom of the bowl to ensure all ingredients are mixed and there are no clumps.
• Add the hot water and whisk well to combine. The batter will be thin and soupy; this is normal.

5. Bake the Cake Layers:

• Pour the batter evenly into the prepared pans.
• Bake for 30 to 35 minutes, or until a wooden pick inserted into the center comes out clean.
• Cool in the pans for 10 minutes, then remove and cool completely on a wire rack (about 1 1/2 hours).

6. Make the Coconut-Pecan Filling:

• Combine the granulated sugar, brown sugar, evaporated milk, melted butter, egg yolks, and salt in a medium saucepan.

• Whisk until smooth.

• Cook over medium heat, whisking frequently, until the mixture just begins to boil and coats the back of a spoon, 10 to 12 minutes.

• Remove from the heat and stir in 1 cup of the coconut, the 2/3 cup chopped pecans, and the vanilla extract.

• Transfer to a bowl, cover, and refrigerate until completely cooled.

7. Make the Chocolate Buttercream:

• Whisk together the sugar and egg whites in the heatproof bowl of a stand mixer.
• Place the bowl over a saucepan of simmering water (make sure the bottom of the bowl doesn’t touch the water).
• Cook, whisking occasionally, until an instant-read thermometer registers 120°F to 130°F (49°C to 54°C), or until the egg whites are foamy and there are no sugar granules remaining when rubbed between your fingers.
• Carefully place the bowl onto the stand mixer fitted with the whisk attachment.
• Beat at medium-high speed until stiff peaks form and the bowl is cool to the touch, 7 to 8 minutes.
• Add the softened butter, one cube at a time, beating until combined after each addition. (If the buttercream appears to break or curdle, continue beating for 2-3 minutes, and it should come back together.)
• Beat in the vanilla extract and salt.
• Reduce the speed to medium-low and beat in the sifted cocoa powder until fully combined.

8. Assemble the Cake: * Place about 1/2 cup of buttercream in a piping bag and cut a 1-inch-wide opening at the tip. * Pipe a ring of buttercream on top of one cooled cake layer, right along the edge. * Spread half of the cooled filling on top of the cake inside the ring. * Place the other layer upside down. * Spread the reamining buttercream. * Place pecan halves around the top of the cake. * Press the additional 1/2 cup coconut. * Refrigerate or store in a cool place.