Making a cake shaped like a bottle is a challenging task because it calls for giving a flat cake a rounded shape. However, you can sculpt the cake into a bottle shape with a little help from crispy rice cereal treats. Some bakers make the entire bottle from crispy rice cereal treats and place it on top of a flat cake. For cake lovers, a better option is to make the body of the bottle from cake, while using crispy rice cereal treats to sculpt a sturdy stem and mouth for the bottle.
Place the cake on a cake plate. Cut the sheet cake in half across its midsection. Coat one half in buttercream frosting, then stack the other half on top. Coat the entire cake in another layer of buttercream frosting. Stick the cake in the freezer and freeze it for two hours.
Remove the cake from the freezer. Use a small serrated knife to shape the cake into the body of the bottle. Make the middle the widest point with the cake tapering at the top and bottom into a rounded shape. Work slowly, and refreeze the cake if necessary. Coat the entire cake in buttercream icing when you are finished sculpting.
Form the crispy cereal treats into the neck and mouth of the bottle. Stick the treats to one end of the cake using a small wood dowel rod.
Coat the cake and cereal treats with rolled fondant. Trim away any excess. Use additional fondant to decorate the bottle, You might make your cake resemble a favourite brand of liquor or add the name of the person who will receive the cake.