A fun birthday idea for a gift is to make a Brownie in a Bottle!   You get a wide mouth jar, spray it with oil, take your brownie mix and fill the jar 2/3 full.  Cook it and when it's done, you can decorate the jar however you wish and the girl has her own birthday cake!  You cook it right in the oven in the jar.  I had to cook it for about an hour. But it was delicious and very easy and fun!  

* ANOTHER VERSION:  Instead of cooking the brownies, layer the ingredients in a bottle with instructions on how to bake.  Here are instructions on how to do that.