Royal icing is made from egg whites and pure icing sugar, along with a tiny amount of lemon juice. When beaten together, they form royal icing. Royal icing doesn't hold its shape for long periods of time, so when decorating wedding cakes, use royal icing to cover the cake and create tiny details like dots rather than large wedding decorations such as flowers. When iced, the wedding cake will be covered with a hard and shiny coat of royal icing.
Set the cake on top of a cardboard cake round. This cake round should be the same size as the cake.
Cover the cake with a thin layer of apricot jam. Sift the jam several times through a small strainer to remove seeds and lumps and then coat the cake with the jam. If the jam is too thick to work with, warm it in the microwave to thin it and make it easier to spread. Use a pallet knife to spread the jam.
Knead the marzipan to soften it and make it easier to work with. Fold the marzipan in half and press down firmly in the middle, which flattens the marzipan out. Fold in half and repeat. Fold the marzipan front to back one time and fold it left to right the next so you're preparing the marzipan evenly. Do this several times to soften the marzipan.
Scatter some icing sugar, which is confectioner's sugar, onto the counter and roll the marzipan with a rolling pin. Keep the same side facing up and move the marzipan in 45-degree turns. Roll it until it's large enough to cover the top of the cake and drape down over the sides of the cake.
Slide your hands under the marzipan and pick it up. Drape it over the top of the cake so the same amount of marzipan is draping down over each side of the cake. Rub the top of the marzipan gently over the top of the cake to remove any air bubbles between the marzipan and the cake.
Smooth the marzipan down the sides of the cake, pulling to remove any gaps and pressing the marzipan to the cake with the side of your hands. Do not pleat the marzipan, keep smoothing the marzipan with your hand until it's firmly in place on the side. Cut away the excess marzipan with a sharp knife at the base of the cake. Allow the marzipan-covered cake to rest for two or three days so the marzipan fully hardens.
Apply a large dollop of royal icing on the center of your cake.
Hold a palette knife on the top of the cake and turn the cake rather than moving the palette knife to spread the royal icing around the top of the cake. Apply a layer of royal icing about 1/4 inch thick.
Hold a clean, metal ruler at a 45-degree angle, slightly above the cake, and pull it across the top of the cake, removing the excess royal icing and leaving a perfectly smooth surface behind.
Apply a thin layer of royal icing to the sides of the cake. Apply it as smooth as possible and to a depth of approximately 1/4 inch deep.
Hold a palette knife against the side of the cake so the knife is vertical. Spin the cake, holding the knife still, smoothing the royal icing. Remove the excess icing.
Place your palette knife at a 45-degree angle along the edge where the side of the cake meets the top of the cake. Rotate the cake while holding the palette knife in place to remove the excess icing from that seam. Allow the cake to sit for three days so this first coat of royal icing hardens.
Apply a second coat of royal icing in the same way as the first. Allow the royal icing to dry for three days. Remove any rough edges by lightly sanding the icing with high-grit sandpaper. Carefully wipe away the dust from the cake.
Fill a piping bag with royal icing and insert a small, plain tip. Pipe small dots around the top of the cake, making all of the dots the same size. Place each dot directly up against the previous one, with no gaps in between them. Pipe a second row of dots inside the first row.
Pipe dots around the sides of the cake, filling the sides completely with the royal icing dots.
Make a second cake, smaller than the first. Cover it in marzipan and two layers of royal icing. Pipe two rows of dots around the top edge and fill the sides with royal icing dots. Center this smaller cake in the center of the first cake to create a layered wedding cake. Add as many layers as you'd like, with each layer progressively smaller than the previous layer. Top with white roses.
Weigh the cake and use half that weight in marzipan to cover the cake.
Pipe lines, swags or diamond patterns on your wedding cake for more elaborate decor.
Practice working with marzipan, royal icing and piping to perfect your skills before you make your wedding cake.