For the Cake: Preheat oven to 350°F (180° C) and place rack in center of oven. Butter and flour three - 8 inch round cake pans. Line bottoms of pans with parchment paper and grease and flour parchment paper. While eggs are still cold, separate them, 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 medium mixing bowl, sift together the flour, baking powder and salt. In the bowl of an electric mixer, beat the butter until soft (about 1-2 minutes). Add 1 1/2 cups of the sugar and beat until light and fluffy (about 5 minutes). Add egg yolks, one at a time, beating after each addition. Scrape down the sides of the bowl. Add the vanilla and beat until combined. With the mixer on low speed, alternately add the flour mixture and milk, in three additions, beginning and ending with the flour. In the clean bowl of your electric mixer fitted with the whisk attachment, beat the egg whites until foamy. Add the cream of tartar and continue beating until soft peaks form. Gradually add the remaining 1/2 cup 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. Divide the batter evenly between the three prepared pans and smooth the tops with an offset spatula. Bake in preheated oven for approximately 25 minutes, or until a toothpick inserted into the center of the cake comes out clean. Cool the cakes in their pans on a wire rack for 10 minutes. Place a wire rack on top of the cake pan and invert, lifting off the pan gently. Once the cakes of completely cooled, wrap in plastic and place the cake layers in the freezer for at least an hour (to make filling and frosting the cakes easier). For the Icing (Classic): In an electric mixer fitted with the paddle attachment, beat the butter and icing sugar on low speed until just combined. Increase speed to medium and beat until well-incorporated, about 3 minutes. Add the vanilla, water, whipping cream and salt, and whip on med-high speed until fluffy and smooth--about 3 more minutes. If consistency is too thick, add more water 1 teaspoon at a time, then whip again for 30 seconds or so. If your frosting is too thin, you can add more icing sugar a few tablespoons at a time until you achieve desired consistency. For the Icing (Cream Cheese): Cream the butter on medium speed until the butter turns whitish and glossy, about 3-5 minutes. Add 1 cup of icing sugar and mix with the butter on medium speed until its all mixed well and glossy again. Add the cream cheese, continue mixing with the electric mixer until everything is well mixed. Start adding the rest of the icing sugar, one cup at a time to the mixture, and continue mixing on medium speed. When all the sugar is mixed well, add the vanilla extract. Cake Pop Assembly: Mix the cake and the icing in a bowl. Roll into balls and place on wax paper. Refrigerate for 10-15minutes. Melt a little candy coating, dip the lollypop sticks in the coating before inserting them into the cake balls. Place in the freezer for 1 hour. Melt the rest of the candy coating. Add color of your choosing...and if you want to thin the candy coating you can add a little vegetable oil or shortening to thin it. Coat the cake pops with the candy coating....if you want the cake pops to stay perfect on top, then you can insert the stick into a foam block (can be found at Michael's or any florist). You can add sprinkles and other decoration while the coating is still wet.