Preheat oven to 350F.

Line the base and sides of an 8-inch cake pan with parchment paper; set aside.

Combine butter and sugar in your mixer's bowl; beat for 5 minutes on medium speed.

Add lime zest and lime juice; continue to beat for 3 to 4 minutes, or until mixture is pale and creamy.

Scrape down the sides of the bowl and with the mixer on, add the egg yolks, one at a time, continuing to beat until combined.

Add the almond flour and continue to beat until thoroughly combined.

Using a rubber spatula, fold in the ricotta and coconut. Set aside.

In a clean bowl, beat the egg whites until soft peaks form.

Gradually add 1/3-cup sugar to the egg whites and continue to beat until stiff peaks form.

Using a rubber spatula, fold a third of the egg whites into the cake batter.

Fold in the rest of the egg whites until thoroughly incorporated.

Transfer the batter to the previously prepared cake pan and smooth the top.

Bake for 35 to 40 minutes, or until a toothpick inserted in the center of the cake comes out clean.

Remove from oven and transfer to a wire rack; let completely cool in the cake pan.

In your mixer's bowl, cream the butter until smooth.

With the mixer on low speed, gradually beat in the powdered sugar.

Scrape down the sides of the bowl.

Add the salt, vanilla and lime juice; beat on high speed until frosting is light and fluffy, about 5 minutes.

Add the lime zest and beat just until incorporated.

Spread the frosting on the completely cooled cake.

Sprinkle coconut flakes on top.

Cut and Serve.