Preheat oven to 350 degrees F. Line a muffin tin with 12 cupcakes liners.
In a large mixing bowl, combine flour, cornstarch, baking powder, baking soda, and salt. Set aside.
Use can electric mixer to beat butter and sugar together until light and fluffy. Mix in the the banana, buttermilk, and eggs until combined. Add in the dry ingredients a little at a time while mixing, until combined. Divide batter among the liners (an ice cream scoop works perfect for this!) and bake for 15-18 minutes or until toothpick comes out clean.
Remove cupcakes from tin and allow to cool on a rack.
For the Frosting:
With an electric mixer, beat butter, sugar, and vanilla together until smooth. Add cream until you get desired consistency. Place in a piping back that is fitted with a large round tip and then pipe onto cooled cupcakes.
For the ganache:
Place chocolate chips in a bowl. Place whipping cream in another dish and microwave until hot (about 45 seconds). Pour hot whipping cream over the chocolate chips and let it sit for 2 minutes and then stir together until completely melted and combined. Allow the ganache for cool down for a few minutes before spooning onto the frosting.
For the Toppings:
Add sprinkles on top of the ganache. Pipe a little whipped cream on and then top with a cherry. Serve. (Cupcakes can be made ahead of time but wait to add the whipped cream and cherry until right before serving.)