The recipe I use for my cupcakes is a texas sheet cake. The same one The Pioneer Woman uses. I just fill the cupcake liners a little more than 2/3 full and bake between 18-20 minutes at 350.
After the cupcakes were fully cooled I hollowed out a center hole into the cupcakes. You can achieve this by using an apple corer, a paring knife, a skinny spoon like a grapefuit spoon, etc. My fancy gadget of choice was this funny little orange juicer we got as a freebie once. I twisted it in about 2/3 of the way down and pulled out the plug. It was perfect.
After they were all hollowed out, I started making my ganache. I used
8 oz of good quality semi-sweet chocolate chips (or your flavor preference)
2/3 cup heavy cream
2 Tbsp of butter.
Put the chocolate chips in a heat proof bowl, set aside.
In small sauce pan, heat the cream until simmering (dont scald)
Pour hot cream over the chips in the bowl, let sit for 1 minute, then stir until smooth.
Add butter, stir until combined. If the chips dont melt all the way, you can put the bowl over a sauce pan of boiling water and continue stirring until smooth.
Let ganache sit until cool enough to transfer to a piping bag or squeeze bottle.
I used a buttercream recipe that I got from Amanda at i am baker (scroll to find the Magnolia buttercream recipe).
The finished product: