Preheat your oven to 350°F and grease two 9-inch round cake pans (or similar size), then set them aside. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt—this prevents lumps and ensures even leavening throughout the cake. Let all your eggs, cream cheese, and butter come to room temperature if they haven't already, as this is crucial for proper emulsification and a tender crumb. I like to separate my eggs while they're still slightly cool, which makes it easier to get clean whites without any yolk contamination.

In a large bowl, cream together 8.5 oz softened butter and 1 2/3 cups sugar for about 2 minutes until light and fluffy—this incorporates air which helps the cake rise. Add the 13.5 oz cream of coconut and beat until well combined, creating a rich coconut base. Now add the egg yolks one at a time, beating after each addition to fully incorporate, then add the vanilla extract and mix until smooth. The emulsion you're building here is what keeps the cake moist and gives it that tender crumb texture.

Add the dry ingredient mixture from Step 1 to the batter in three parts, alternating with the buttermilk in two parts, starting and ending with the dry ingredients. Mix on low speed or by hand just until combined after each addition—overmixing develops gluten and makes the cake tough. This alternating method ensures the flour is evenly distributed and keeps the batter light and tender.

In a separate clean bowl, beat the 4 egg whites with 1/4 tsp salt until stiff peaks form—this incorporates maximum air into the whites. Gently fold the whipped egg whites into the batter from Step 3 using a spatula, working in two additions and being careful not to deflate them. This folding technique keeps the air bubbles intact, which creates a light, airy texture in the final cake. I make sure to scrape the bottom of the bowl while folding to incorporate any heavier batter that settles.

Divide the batter evenly between the two prepared pans and smooth the tops. Bake in the preheated 350°F oven for 40 to 45 minutes, until a toothpick inserted into the center comes out clean or with just a few moist crumbs. The cakes will be golden brown and spring back slightly when lightly touched. Let the cakes cool in their pans for about 10 minutes, then turn them out onto a wire cooling rack and cool completely before frosting.

Once the cakes have cooled completely, beat 16 oz softened cream cheese in a large bowl for about 3 minutes until smooth and fluffy. Add 5 oz softened butter and beat again until the mixture is smooth and well combined. Add the sifted confectioners' sugar, 1/2 cup cream of coconut, 1.5 tsp vanilla, and 1/2 tsp lime zest, then beat for another 3 minutes until light and creamy. The lime zest adds a subtle brightness that complements the coconut beautifully without being too obvious.

Place the first cooled cake layer on your serving plate or cake board. Spread about 1 cup of the frosting from Step 6 on top of the first layer, then sprinkle 1 cup of shredded coconut over the frosting. Set the second cake layer on top and gently press down. Cover the top and sides of the entire cake with the remaining frosting, then press the remaining shredded coconut onto the frosting to coat evenly. Chill the finished cake for at least 1 hour before serving—this helps the frosting set and the flavors meld together beautifully.