Preheat the oven to 350 degrees, grease and flour three 8×2 inch round pans.

In a medium bowl, whisk the flour, baking powder, baking soda and salt for 30 seconds. Set aside

In another bowl, add the buttermilk, oil, vanilla extract, and coconut extract.  Set aside..

In the bowl of your mixer, add the butter and mix at medium speed until smooth. Gradually add the sugar and continue to mix on medium speed for 3 to 5 minutes until lightened in color and fluffy. Add the eggs one at a time mixing until the yellow of the yolk disappears.

With the mixer on low speed, alternately add the flour mixture and buttermilk mixture, beginning and ending with the dry ingredients (3 additions of dry ingredients and 2 of liquid). After the last addition, slightly increase the mixing speed until combined.

Do not mix above medium speed or over mix the cake batter.

Bake at 350 degrees for 25-30 minutes or until a toothpick inserted in the center comes out clean or with just few crumbs attached. Let cool 10 minutes and turn out.

In a medium bowl, whisk egg yolks and set aside.  

In a saucepan, combine the sugar, cornstarch  and salt.  Whisk to blend.

Gradually stir in the milk and coconut milk.

Cook over medium heat stirring constantly to dissolve the sugar.

Bring the mixture to a simmer.  Remove the saucepan from the heat.  Spoon ¼ to ½ cup of the hot mixture into the bowl holding the egg yolks, stir constantly to temper the eggs. (You are tempering the eggs so you will not have small pieces of scrambled egg when you pour them back into the simmering saucepan).  

Pour pastry cream into a heat proof bowl or small flat casserole dish for faster cooling.  Immediately cover with plastic wrap, pressing the wrap against the filling to prevent a skin from forming. Refrigerate until throughly cold before using. If you do not need it right away it can be refrigerated for 3 days, possibly longer.

Freeze your mixing bowl and beaters 15 minutes before whipping the cream (30 minutes if chilling in the refrigerator. 

In another bowl combine the cream cheese, powdered sugar, coconut extract, and vanilla.  Beat until very smooth.  Fold this into the whipped cream. Cover and refrigerate.  If you are piping this frosting and it becomes too soft, just refrigerate the filled piping bag for a short while.  

Place the first cake layer on the cake plate or pedestal. Spread with the coconut pastry cream. I do not take it all the way to the edge- leave about ¼ inch to ½ inch of space so that when the layers are stacked, the filling isn't pushed out..

Repeat for the second cake layer and the third. Fill in any gaps between the cake layers with the whipped coconut cream cheese frosting (I usually use a disposable piping bag with the tip snipped away for this.).

Apply a layer of the whipped cream cheese frosting. I applied in thin on top because I also added a layer of the coconut pastry cream to the top center of the cake. Apply flaked coconut around the sides of the cake.

I added a top border of rosettes using a large star 1M tip. (2D is a good choice also)

Cake should be refrigerated. Remove from the refrigerator a couple of hours before serving for best texture and flavor!