Make the cupcakes

1. Preheat oven to 350°F (176°C) and prepare a cupcake pan with cupcake liners.
2. Combine the flour, baking powder, baking soda and salt in a medium sized bowl and set aside.
3. In a large bowl, whisk the melted butter, brown sugar and vanilla extract together until well combined.
4. Add the eggs and whisk together until well combined. Next, add the sour cream and whisk together until well combined. Now, add the milk and whisk together until well combined.
5. Add the dry ingredients and whisk together until combined, but do not over mix.
6. Fill the cupcake liners a little more than 3/4 full (60g) and bake for 15-20 minutes or until a toothpick inserted into the center comes out clean.
7. Remove cupcakes from the oven and place on a cooling rack to cool.

Make the frosting

1. While the cupcakes bake and cool, make the frosting. Melt the butter in a medium sized saucepan. Add the brown sugar and heavy cream and whisk constantly over medium heat until sugar is dissolved.
2. Bring to a boil and allow to boil for 3 minutes. Remove from heat, pour into a bowl and allow to cool to room temperature. It will become quite firm and may get a little grainy. When you stir it, it will be crumbly and dry.
3. Transfer crumbly caramel to a large mixer bowl and add 2 cups (230g) of powdered sugar. Mix until well combined. Mixture will be crumbly and not come together yet. Add 4 tablespoons of heavy cream and mix until well combined. It should start to smooth out now.
4. Add the remaining 2 cups (230g) of powdered sugar and mix until well combined. It shouldn’t be as crumbly as before, but it may be a little dry.
5. Add additional heavy cream, as needed, to get the right frosting consistency. The frosting may be a little gritty at first, but that will dissolve away as it sits.

Make the filling

1. Add the shortening to a large mixer bowl and beat until smooth.
2. Add the powdered sugar, vanilla extract and water and mix until well combined and smooth. Filling will be thick.

Put the cupcakes together

1. When the cupcakes have cooled, use a cupcake corer to remove the centers from the cupcakes.
2. Fill the cupcakes with a tablespoon of filling in each cupcake.
3. Pipe the buttercream on top of the cupcakes. I used Ateco tip 809. For help with creating the dome shape frosting, refer to my tutorial for frosting cupcakes. Top each cupcake with a caramel cream candy.
4. The cupcakes should be stored in an air-tight container. They are fine at room temperature for about 24 hours, but then should be refrigerated. Serve at room temperature. Cupcakes are best if eaten within 3-4 days.