Place water and sugar in a small saucepan to make a simple syrup.Bring to a boil and continue to simmer until sugar has dissolved.Let cool before using.Place one cake layer on cake turntable. Use a serrated knife to goaround the top edge of the cake layer to score it before leveling offthe domed cake top, so you get a flat, even cake layer. Once scoredand the height is the same around the cake, use the serrated knife ina sawing motion, going back and forth slowly to remove the cakedome (cake scraps make an excellent trifle!). Repeat for all four layers.Place first layer of cake on turntable. Use a pastry brush to moisten the top of the layer with syrup evenly.Spread ¾ cup buttercream on top of cake with a small offsetspatula. Make sure to spread all the way to the edges of cake (butnot on the sides). Place next cake layer on top, gently pressing downto make sure cake is even and secure. Repeat with each layer. Spread1 cup buttercream on outside of cake, working the small offset spatula back and forth to cover entire exterior of the layered cake.Crumbs may fall off, but that’s okay, the buttercream will act as aglue to adhere crumbs to the cake. Clean up and smooth the surfaceby keeping the offset spatula flat on top while spinning the caketurntable. For the sides, hold the offset spatula upright and turncake turntable to smooth buttercream. This is the crumb coat. Chillin refrigerator 30 minutes. Remove chilled layer cake. Spread ¾ cup buttercream on top andsides of cake. Use small offset spatula to apply final coat of frosting.Decorate as desired.