Place your 6oz of chocolate into a microwave safe bowl. You can use semi-sweet chocolate chips or bakers chocolate. I went with a bar of bakers chocolate, so whichever is more convinent will work.
Then you'll want to add your ¼ cup of whipping cream and 3tbsp of butter, so that all three ingridents are together.
Next, microwave until the chocolate starts to melt. This should take about 1-2 minutes but I recommend starting on the lower end of time so that you don't burn your chocolate.
Finally, whisk the chocolate until it becomes creamy. Then place it into the fridge to cool. If you find your ganache is runny, once it's cooled a little you can use an electric hand held mixer to whip it together. Place it back in the fridge until you're ready to use it and that should help it thicken.
Once your cupcake is completely cool, core our the center being sure to not go all the way through the cupcake. I used a corer but you can use just a knife or apple corer.
Fill a pipping bag with you ganache and pipe it into the center of your cupcake. Putting the cored out top back over the filling.