Found some ideas, including fudge -
Truffles – Once the ganache is chilled you can scoop it out into little truffle balls. Dust them in cocoa powder or roll them in chopped nuts or shredded coconut and you have a perfect little treat.
Chocolate Dip – Warm the ganache and use it to dip your favorite goodies in. Things like brownies, cookies, candies, or even Rice Krispie Treats work great! Sprinkle a little crushed cookie or nonpareils on after dipping and you’ve just turned a simple treat into something much more decadent.
Fudge – If you have plain leftover ganache simply warm it up a bit and then stir in whatever mix-ins you prefer such as: nuts, sprinkles, candies, or even dried fruit. Spread in a pan and chill until firm then cut into bite sized pieces.
Chocolate Mousse – Add a little double cream to the leftover ganache and whip in a stand mixer until it reaches a mousse like consistency. Spoon into serving glasses and serve with a dollop of whipped cream!
Chocolate Fondue – Warm the ganache and serve it in a small bowl as a fondue alongside a plate of pretzels, pound cake, fresh fruit, cookies, or marshmallows for dipping.
Frosting/Filling – Use the leftovers as frosting for a batch of cupcakes. Better yet, use the ganache as a delicious filling inside of your cupcakes.