Special equipment: 1 (28-inch-diameter) plywood base 7 feet 4 inches 3/4-inch-wide ribbon 1 30 by 40-inch piece 3/16-inch-thick foam board 1 each cardboard cake rounds in the following diameters: 18, 12, and 6 inches 8 (7-inch-high) clear plastic tapered columns
Prepare the base: Working on a flat surface, draw a circle in the center of plywood base that is 2 to 3 inches smaller than the largest cake tier. Using a large offset spatula, spread royal icing over surface between the drawn circle and edge of round plywood board to coat surface smoothly. Tap board on work surface to smooth and eliminate any bubbles. Set aside to dry, about 24 hours. When royal icing is dry, glue ribbon to side of board, wrapping around to cover entirely. Cut foam board into rounds, 1 each of the following diameters: 18, 12, and 6 inches. When cakes have completely cooled, place 1 of each size cake right side up on its corresponding size foam-board round. Place remaining 3 tiers on corresponding size cardboard cake rounds. Wrap all cakes tightly in plastic, and chill for at least 6 hours. (This makes the layers firm and easy to handle.) Cakes can also be frozen at this point. Remove cakes from refrigerator. If cakes are not level, use a serrated knife to trim the tops off, making sure to maintain a 2-inch height on each cake. Place 1 of each cake on the corresponding size foam-board rounds, cut side up. Brush the cut surface of the bottom base cake layers generously with Lemon Simple Syrup. Using a medium-large pastry bag fitted with a coupler, pipe soft Italian meringue around the perimeter of each cake that has been moistened with syrup. This "dam" will prevent the lemon curd from seeping out. Fill the 18-inch cake layer with 4 2/3 cups lemon curd, the 12-inch cake layer with 2 1/3 cups lemon curd, and the 6-inch cake layer with 1/2 cup lemon curd. Place the remaining cake layers, cut side down, on their corresponding size lemon curd filled cakes. Brush tops generously with Lemon Simple Syrup. Using an offset spatula to give each tier a "crumb coat," ice top and sides of cake with a thin coat of soft Italian meringue. This thin layer of icing will seal the cake. Start from the center, and work toward and over the edge, making sure to spread the meringue over the sides of the tier. Let dry at room temperature for 30 minutes. To ice the cakes: Using a clean offset spatula, spread a smooth, even layer of soft Italian meringue, to coat cake entirely. Be sure to cover all exposed cake. The icing should be smooth and uniform. Place the largest tier on the serving platter. Insert 4 columns, narrow side down, into the 18-inch tier; each column should be 4 inches from the edge of the cake and evenly spaced around the cake. Fill a large pastry bag, fitted with a large star (number #869) tip, with a freshly made batch of meringue. Beginning from the center, pipe 2 1/2-inch cones to cover the entire top of tier. Insert columns into the 12-inch tier; pipe 12, and 6-inch tiers in the same manner as in step 6. When ready to assemble the cake, dab a small amount of meringue onto the top of each column to fasten it to the above tier. Carefully stack the tiers.
Twelve batches of batter are needed to yield 2 (6-inch) round layers, 2 (10-inch) layers, and 2 (14-inch) layers. Fill each 6-inch pan with 1 3/4 cups of batter. Fill each 10-inch pan with 5 cups of batter. Fill each 14-inch pan with 11 cups of batter. Heat oven to 350 degrees F. Butter baking pans; line bottom of each baking pan with a round of parchment paper. Butter parchment and dust pans with flour, making sure to coat pans evenly. Tap out excess flour. In the bowl of an electric mixture fitted with the paddle attachment, cream butter and sugar until light in color and fluffy, about 5 minutes. Add vanilla extract, then the eggs, 1 at a time. Sift together flour, salt, and baking powder 3 times. Add to egg mixture in 3 additions, alternating with milk, starting and ending with flour. Measure batter into prepared pans. Bake 6-inch rounds for about 35 minutes, 10-inch rounds for about 45 minutes, and the 14-inch round for about 1 hour and 10 minutes. Cakes are done when the tops are golden brown and a cake tester inserted into center of cake comes out clean. Yield: 3 cups batter
In the bowl of an electric mixer fitted with the paddle attachment, combine confectioners' sugar, meringue powder, and egg white. Mixing on low speed, add 1/4 cup water. Mix until icing begins to come up the side of the bowl, about 5 minutes. Add an additional tablespoon water, and mix until icing holds a ribbon-like trail on the surface for 5 seconds when you raise the paddle. If more water is necessary, add more, drop by drop, until the proper consistency is achieved. Yield: 2 cups
In a large heavy saucepan, bring 4 cups of water and the sugar to a rolling boil. Remove from heat, and add lemon juice. Let stand at room temperature to cool. Set aside. (Can be made several days in advance.) Yield: 7 cups
In a small, heavy-bottomed saucepan, whisk together egg yolks and whole eggs. Add sugar and lemon juice. Set over low heat, and cook, stirring constantly, until mixture coats the back of a wooden spoon, 8 to 10 minutes. Remove pan from heat, and stir to cool slightly. Strain curd through a sieve set over a small bowl. Add butter, a piece at time, stirring until smooth after each addition. Stir in lemon zest, and let cool completely. Yield: 1 1/2 cups
In a small saucepan, bring sugar and 2/3 cup water to a boil. Boil until the syrup reaches the soft-ball stage (238 degrees on a candy thermometer). Meanwhile, in the bowl of an electric mixer fitted with the whisk attachment, beat egg whites on low speed until foamy. Add cream of tartar; beat on medium high until stiff but not dry. With the mixer running, slowly pour the hot sugar syrup into egg whites, and beat on high speed until mixture has cooled, about 15 minutes. Use immediately. If the meringue is overbeaten or is not used immediately, it will contain too many air bubbles that will make holes when piped. Yield: 6 cups *RAW EGG WARNING Food Network Kitchens suggest caution in consuming raw and lightly-cooked eggs due to the slight risk of Salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly-refrigerated, clean, grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell.