Preheat your oven to 350°F (175°C). Grease and flour your two 9-inch round cake pans to prevent sticking.
In a large mixing bowl, beat the 6 large eggs and 1 cup of granulated sugar together until light and fluffy. This should take about 3-5 minutes.
In another bowl, whisk together 1 cup of all-purpose flour and 1 teaspoon of baking powder. Gradually add this dry mixture to the egg and sugar mixture, mixing until just combined.
Add 1/4 cup of freshly squeezed lime juice and 3/4 cup of warm water to the batter. Mix until fully incorporated, ensuring a smooth consistency.
Divide the batter evenly between the prepared cake pans. Bake in the preheated oven for 25-30 minutes or until a toothpick inserted into the center comes out clean. Allow the cakes to cool in the pans for about 10 minutes before transferring them to a cooling rack to cool completely.
In a mixing bowl, beat 8 oz of softened cream cheese with 1 cup of granulated sugar until creamy. Add 16 oz of cold full-fat sour cream, 3 tablespoons of freshly squeezed lime juice, and 1 tablespoon of lime zest. Mix until smooth and well combined.
Once the cakes are completely cool, place one layer on a serving platter. Spread a generous amount of frosting on top of the first layer, then sprinkle with 1 cup of sweetened shredded coconut. Place the second layer on top and frost the top and sides of the cake with the remaining frosting. Decorate the top with additional coconut if desired.
Refrigerate the cake for at least 30 minutes before serving to allow the flavors to meld together. Slice and enjoy your refreshing Key Lime Coconut Cake!
