Preheat oven to 350 degrees and line a cupcake pan with liners.
In a small bowl, whisk together flour, baking powder, baking soda, and salt; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, cream butter until it is light and fluffy.
Add the sugars and beat until well combined.
Add the eggs, one at a time, beating well after each addition. Mix in vanilla and butter flavoring.
Beginning and ending with the buttermilk, add the cream soda, and flour a little at a time, mixing well after each. Scrape the side of the bowl with a rubber spatula if necessary.
Place batter into cupcake liners about 2/3 full, and bake for 15-17 minutes, or until the tops are lightly golden.
Remove to wire racks to completely cool.
Fill a squeeze bottle with the ganache and insert the top of the bottle into the center of one of the cupcakes.
Squeeze until filling begins to overflow.
Repeat with remaining cupcakes.
Frost cupcakes and drizzle with butterscotch ganache.
Butterscotch Ganache
In a heatproof bowl set over a pan of simmering water, combine chips and cream.
Stir until chips are melted and ganache is smooth.
Remove from heat and allow to cool to room temperature.
Buttercream Frosting
In a clean bowl of an electric mixer, fitted with the whisk attachment, cream butter until light and fluffy.
Add ganache, vanilla, butter flavoring, and salt. Mix well.
Add powdered sugar, one cup at a time, incorporating well after each addition.
After all of the sugar has been added, the frosting will appear dry.
Add cream, one tablespoon at a time, until frosting is smooth and creamy.