For a music lover's birthday, a guitar cake makes a special gift. Creating an acoustic guitar shape requires a model for colouring and design, so you need a picture or real guitar to see all the elements of the cake. In addition, there are guitar pans that make creating the look of a guitar-shaped cake easier. Other ingredients you need are red, black, and blue food colouring and a basic vanilla or chocolate cake mix.
Make buttercream icing using 240 ml (1 cup) of milk, 90 ml (5 tablespoons) all purpose flour, 360 ml (1.5 cup) brown sugar, 240 ml (1 cup) butter, 18 ml (1 tablespoon) vanilla, and 6 ml (1 teaspoon) salt (if using unsalted butter). Stir the milk and flour together, then mix over medium heat for 5 to 10 minutes until thick.
Set milk/flour mixture aside to cool, and mix sugar, butter and vanilla in mixer. Beat the mixture on medium speed for 5 to 10 minutes until smooth, then add the milk mixture and stir until smooth.
Tint 240 ml (1 cup) of buttercream icing to light brown using red and blue food colouring. Tint a second cup of buttercream icing to a dark brown, and a third cup with black colouring. Keep another 180 ml (3/4 cup) of white vanilla frosting on hand. Store containers in refrigerator until ready to decorate.
Tint approximately 120 ml (1/2 cup) melted white candy black using red and blue candy melts. Candy darkens while cooling in the fridge. Use the black candy melt to mould the fingerboard, bridge, and sound hole in the centre of the guitar pan. Use the light cocoa candy to use for the headstock.
Mix your cake's ingredients together following the package instructions but replace your circular pan for a guitar pan. Alternatively, cook in a large cake pan and cut the shape of the acoustic guitar from the cake square after cooling.
Trace the pattern of the acoustic guitar on large waxed paper with a non-toxic marker or pencil. Ice the cake with a base coat of icing, then place the waxed paper pattern on the cake. Push toothpicks down into the cake along the traced pattern lines to create the pattern on the cake.
Remove all the toothpicks and paper, then connect the dots with icing outlines in relevant colours using a 3 round tip with the icing bag. Use a picture or real acoustic guitar as a model for colouring and designing the icing lines.
Spread the light brown icing with a spatula on the top area of the cake. Let the icing sit until slightly hardened. Ice the sides and body of the guitar cake until smooth. Spread icing thinly around fingerboard and neck.
Fill an icing bag with your light brown icing, then use an 18 tip to create individual icing stars around the outer border of the guitar's body, then fill in the guitar's body with star-shaped icing. With a 3 tip and black icing, create the pick guard pattern at the centre of the guard, then fill in with 18 tip stars.
Place the candy plaques for the fingerboard, bridge and tuners on to the cake and use tip 3 and white icing to create frets and strings of the guitar.