White Cupcakes: Preheat oven to 350 degrees F (177 degrees C) and lightly butter or line 12 muffin cups with paper liners.

Separate the eggs while they are still cold, placing the yolks in one bowl and the whites in another bowl. Cover the two bowls with plastic wrap and allow the eggs to come to room temperature before using (about 30 minutes).

In a mixing bowl sift or whisk together the flour, baking powder, and salt. Set aside.

In the bowl of your electric mixer, or with a hand mixer, beat the butter until soft (about 1-2 minutes). Add 3/4 cup (150 grams) of the sugar and beat until light and fluffy (about 2-3 minutes). Scrape down the sides of the bowl. Add egg yolks, one at a time, beating well after each addition. Scrape down the sides of the bowl. Beat in the vanilla extract and lime peel (if using). Then, with the mixer on low speed, alternately add the flour mixture and milk, in three additions, beginning and ending with the flour.  

In a clean bowl of your electric mixer, with the whisk attachment, (or with a hand mixer) beat the egg whites until foamy. Add the cream of tartar and continue beating until soft peaks form. Gradually add the remaining 1/4 cup (50 grams) of sugar and continue to beat until stiff peaks form. With a rubber spatula gently fold a little of the whites into the batter to lighten it, and then fold in the remaining whites until combined. Do not over mix the batter or it will deflate.

Evenly fill the 12 muffin cups with the batter and bake for about 18-20 minutes or until nicely browned and a toothpick inserted into a cupcake comes out clean. Remove from oven and place on a wire rack to cool completely. With a knife or offset spatula, spread frosting on each cupcake. If you want to pipe the frosting, I like to use a large Wilton 1M (open or closed) star decorating tip. Garnish with coconut. These cupcakes are best the day they are made but they can be stored in the refrigerator for a few days. Bring to room temperature before serving.

Cream Cheese Frosting: In an electric mixer, or with a hand mixer, cream the butter until smooth and well blended. Beat in the vanilla extract. With the mixer on low speed, gradually beat in the sugar. Scrape down the sides of the bowl. Add the cream cheese and beat on high speed until frosting is light and fluffy (about 3-5 minutes). 

Makes 12 cupcakes