In the bowl of a stand mixer fitted with a paddle attachment, combine the flour, sugar, cocoa powder, baking soda, salt and baking powder. Stir to combine.

In a separate medium sized mixing bowl, combine the eggs, buttermilk, vegetable oil, hot water or coffee and vanilla. Stir to combine.

With the mixer on low speed, slowly add the wet ingredients to the dry ingredients. Mix for about one minute, until the dry ingredients are incorporated into the wet ingredients. Scrape down the sides of the bowl and mix again for about 30 seconds.

Evenly distribute the batter between the pans, about 16 ounces of batter in each 8-inch or 12 ounces in each 6-inch.

Once cooled, you can level the cakes, wrap in plastic wrap, and store in the freezer until ready to use. If you're storing the cake layers longer than a week, also wrap each layer in foil. 

Preheat your oven to 325 degrees F. Spray the bottom and sides of a 9x13" with with nonstick spray. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, combine the sugar, brown sugar, milk powder, and salt. Mix on low speed until evenly blended.

With the mixer on low speed, add the melted butter and stir for one minute until all the dry ingredients are wet.

Add the heavy cream and vanilla and continue mixing on low speed for about one minute, until any of the white streaks from the cream have completely blended into the mixture. Scrape down the sides of the bowl with a spatula.

With the mixer on low speed, add the egg yolks, stirring them into the mixture until combined. Be careful not to over beat (aerate) the mixture, but certain the mixture is glossy and homogenous.

Pour the filling into the prepared pan and bake for 8 to 10 minutes. You want the filling to be firmer and more set toward the outer edges of the baking pan but slightly jiggly and loose in the center. If the filling is still jiggly all over, give it another 2 to 3 minutes.

Let the filling cool slightly and add the toasted coconut. The filling can be used immediately or stored in an airtight container in the refrigerator. 

Heat your oven to 325 degrees F.

Pour the pecans on a sheet pan and toast in the oven for 15 minutes.

In a food processor or blender, puree the warm pecans with grapeseed oil, salt and brown sugar.

In a small mixing bowl, combine the pecan butter with the crushed wafer cookies. The crunch can be stored in an airtight container at room temperature for 5 days or up to 2 weeks in the refrigerator. 

In a microwave safe bowl, heat the cream and then pour it over the chocolate to melt. Stir until the mixture is smooth and silky. If needed heat the mixture for another 20 to 30 seconds and stir until the chips are melted. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter until smooth and light in color, about 2 minutes.

Turn the mixer to medium-low and gradually add the melted chocolate ganache. Stop the mixer and scrape down the sides of the bowl. Beat again for about one minute.

Gradually add the powdered sugar, one cup at a time, followed by the salt and vanilla.

Turn the mixer to medium-high speed and beat for 5 minutes.

Frosting can be store in an airtight container in the refrigerator for a week.

When you're ready to frost the cake, bring the frosting back to room temperature and mix by hand with a wooden spoon to push out all of the air pockets. 

On a cake board, spread a dollop of frosting to act as "glue" to the cake. Place the first cake layer, top side up, on the center of the cake board. You will have a little edge of the cake board showing around the cake.

Spread about 3/4 cup of the buttercream, followed by one half of the coconut crack filling on the cake layer and then one half of the pecan crunch.

Place the second cake layer, top side up, on the fillings and repeat step 3.

Place the final cake layer, top side down, on the second layer of fillings. Apply a thin coat of frosting around the entire cake to lock in the crumbs. Place the cake in your freezer for 10 minutes to set the frosting.

Remove the cake from the freezer and continue to frost the cake with the remainder of the frosting.

If you want to pipe swirls or any decorate design on the cake, I suggest adding another half recipe of the chocolate frosting to what is listed above.