Preheat your oven to 350 degrees F. Prepare three 9-inch round cake pans by either greasing and flouring the inside, or greasing and laying down a round piece of parchment paper on the bottom of each pan.
In a medium mixing bowl, whisk together the all-purpose flour, baking soda, and baking powder. Set aside.
In the bowl of a stand mixer with the paddle attachment (or in a large mixing bowl with a hand mixer) beat together the unsalted butter, Greek yogurt, and sugar until it looks pale and fluffy, about 5 minutes.
Add in egg yolks and vanilla and mix again until combined and smooth. Add half of the flour mixture and half of the buttermilk to the cake batter and beat on low for about 1 minute. Repeat and beat until silky.
Using a Rubber spatula (or the mixer on low speed) mix in coconut flakes and chopped pecans until just incorporated. Divide the cake batter, evenly between the prepared cake pans.
Bake for about 25 minutes, or until a toothpick inserted in the middle comes out clean (or with a few moist crumbs). *I start to check on the cakes around the 20-minute mark.
Remove the cakes from the oven and place them on a wire rack for about 10-15 minutes. Then remove the cakes and allow them to cool entirely while you prepare your icing. Pro Tip: Freeze your cake layers for about 30 minutes prior to icing them and refrigerate the frosting for about 30-45 minutes before icing the cakes.
Frosting
In a stand mixer bowl with the whisk attachment (or a large mixing bowl with a hand mixer), beat the cream cheese on medium speed until smooth, about 2 minutes.
Add in the powdered sugar and vanilla and beat again until well combined. Scrape down the sides of the bowl as needed. Set aside.
In another large bowl, beat the cold heavy whipping cream until stiff peaks form. Use a rubber spatula to fold the whipped cream into the cream cheese frosting in two additions. (It's important to fold and not mix so that the frosting stays light and airy.)
Assembly
Place one cake layer on a cake stand or serving plate. Spread a layer of frosting over the cake - you want to ensure the center is level. The sides can look a bit sparse, but you can fill them up when you do the sides. Repeat until all 3 layers are frosted. Use the rest of the frosting to cover the sides of the cake.
Once the cake is frosted, I like to pipe dollops of whipped cream around the top edge and decorate with whole or chopped pecans and coconut flakes.
Serve the cake immediately or refrigerate until ready to serve. Remove the cake from the fridge 1-2 hours prior to cutting and serving.
Notes
If you don’t have buttermilk on hand, you can combine 1 cup of milk or cream with 1 tablespoon of white vinegar or lemon juice. Stir that together and let it sit for 5 minutes for using the sour milk.