I don't really want to take credit for this recipe; it is all over the internet! However, I did change up the ingredients to my liking in the case of how much brown sugar and vanilla are used. If you don't like really sweet frosting, go easy on the powdered sugar part. I am not a fan of super sweet frosting, but I did find it necessary to leave in the sweetness here, because it is a nice counter to the buttery flavor. These are really good; enjoy!
Preheat oven to 350 and set-up a cupcake pan with cupcake liners.
Sift together flour, baking powder, baking soda, and salt in a bowl; set aside.
In a separate bowl, using a mixer, beat butter and brown sugar until it is creamed together. Add the eggs one at a time, beat some more after every one. Add vanilla and butter flavoring and beat until well incorporated.
This is a good method to make the cupcakes turn out fluffy. Have at your side the buttermilk and cream soda ready to go...
Fold in 1/3 of the flour mixture. Then fold in buttermilk.
Fold in 1/3 more of the flour mixture, then fold in the cream soda. Finally, fold in the remaining 1/3 of the flour mixture.
Spoon mixture into cupcake liners; fill them just over 3/4 full. Bake about 18 minutes, or until cupcakes are springy, and toothpick from center comes out clean. Transfer cupcakes out of pan and let them cool completely.
Now make your ganache: In a saucepan on low heat, melt the butterscotch chips and heavy whipping cream, stirring occasionally. When it is all melted, pour mixture into another container, and place somewhere out of the way to cool it (like in the fridge).
Now make your butterscotch buttercream: In a mixing bowl, beat together all ingredients except for powdered sugar. Slowly add in powdered sugar and taste. If it is sweet enough for you, then stop adding more sugar!
When ready to decorate cupcakes, use whatever pastry filler you have, or if you don't have one (like me), spoon buttercream into a ziplock baggie and cut off the tip.
Decorate cupcake with buttercream, and drizzle with the ganache. The ganache is so tasty... go ahead and drizzle on a LOT! lol. You will have leftover ganache... store it for more cupcakes, or as a fruit dip, or drizzle into coffee.