The Portrait Game
In the portrait cupcake decorating game, have each girl write down her name and toss it into a hat. Have the girls draw names. They then each draw a portrait, in frosting, on a cupcake, of the girl whose name they drew. Provide sprinkles for creating facial features and hair, and frosting in skin and hair tones. Each child can then present the cupcake to the girl whose face she drew.
The Pass It On Game
Start each girl with a cupcake. Let them decorate their cupcakes for 10 seconds and then shout, "Pass It On!" The girls should then pass their cupcakes to the left and begin decorating the next cupcake in front of them, again for 10 seconds. You can either provide each girl with a different color of frosting and type of sprinkles or, if you don't mind a bit of chaos, you can set all the decorations in the middle of the table. End the game when each cupcake seems to have enough decoration.
The Animal Game
Have the girls go through old wildlife magazines and find pictures of an animal they like. Have the girls each learn one or two facts about their animal of choice. Then, using the pictures for reference, have them decorate the cupcakes with an image of the animal. They can also name the animals and write the names on their cupcake. They should each present their animal and relevant facts to the group before eating their cupcake.
The Best Friends Game
If you have just two girls playing cupcake games, have them decorate cupcakes for each other, with each showing off her knowledge about her friend by decorating the cupcakes with images that her friend would appreciate. When they're finished, have them exchange cupcakes. Be sure to provide frosting colors you know they will love, and encourage each girl to explain what she depicted on the cupcake.