Pipe ‘Happy Birthday’ onto the cake (or a message of your choice) and use the remaining royal icing to stick the piped flowers onto the top and sides of the cake.

Stir in the vanilla, followed by the ... Serve warm in the mug with ice cream, cake frosting or a dollop of jam or lemon curd. If you want to make a birthday cake for one, add 1–2 teaspoons ...