Entirely Elizabeth

Vanilla Cupcakes
Set your oven to 350 °F and line a 12 cavity cupcake baking pan with baking cups or parchment paper.
In a large bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt.
Create a well in the dry ingredients and add the buttermilk, vegetable oil, vanilla extract, and the egg.
Whisk everything together until combined. Do not overmix.
Slowly pour the warm water into the batter, stirring constantly. The batter should be loose with no lumps before moving on.
Divide batter equally into the 12 cavities, filling them 2/3 of the way full. 
Place in oven on middle rack and bake for 15 to 18 minutes. The cupcakes should no longer appear glossy on the top and spring back to the touch. A toothpick test should come out clean.
Let the vanilla cupcakes cool for 10 minutes before removing from cupcake baking pan. Cool to room temperature.

Butterscotch Pudding Filling
Prepare the butterscotch pudding as specified on the package (note the amount of milk is half of what is listed on the box).
Once cooled, place the butterscotch pudding into a piping bag that has a filling tip inserted or a small amount of the bag tip cut off. Refrigerate until ready to use.
Not So Sweet Butterscotch Buttercream
In the microwave, melt the butterscotch chips in three 20 second increments (stirring in between each) until the chips are completely melted and smooth. Set aside to cool.
On medium-high speed beat the room temperature unsalted butter, cream cheese, and vanilla extract for 3 to 5 minutes. It should be light in color and smooth.
Add half the powdered sugar, beat on low speed until it is fully absorbed within the frosting, about 1 minute. Do this again with the remaining powdered sugar.
Slowly drizzle in the cooled but melted butterscotch chips. Beat on medium speed until fully incorporated, about 1 to 2 minutes.
Place the butterscotch buttercream into a piping bag that has an extra large piping tip inserted or the bag tip cut off. Set aside in a cool place until ready to use.

Filling and Decorating the Cupcakes
Using a large piping tip, cupcake corer, or a sharp knife, remove the core of the vanilla cupcakes.
Fill the cupcakes with about one tablespoon of butterscotch pudding filling.
Frost the cupcake with the butterscotch buttercream. and decorate with festive fall sprinkles and butterscotch candies, or as desired.