To make the Cupcakes:
Line a muffin tin with cupcake liners. Preheat the oven to 350 degrees F.
Place butter in a small saucepan on low-medium heat and stir until it melts completely.
Continue cooking, stirring frequently until the milk solids turn brown and the butter smells nutty, about 5 minutes longer (or as long as it takes to start turning golden brown).
Take care not to burn the butter. It will continue to brown even after you remove it from the heat, so take it off early.
Scrape the melted butter and browned bits into small bowl and chill until solidified (about half an hour in the freezer, an hour or so in the fridge).
When ready to make cupcakes, remove from the fridge long enough that the butter is soft enough to be beaten with an electric mixer.
In a large bowl, mix together the flour, baking powder, baking soda, and salt. Whisk to combine and set aside.
In a medium bowl, mix together the cooled butter, sugar, egg, yogurt, milk, and vanilla. Beat well to combine.
Slowly add the wet ingredients to the dry ingredients and mix until there are no more lumps - do not over mix.
Evenly distribute the batter among the cupcake liners and bake for 20 - 22 minutes, or until they are golden brown and spring back when you touch them. Set aside to cool.
To make the Knob Creek Frosting:
Beat butter at medium speed with an electric mixer until very pale and creamy.
Gradually add powdered sugar alternately with bourbon and milk, beating at low speed until blended after each addition.
Top with The Art of Caramelís Kentucky Bourbon Black Pepper Carameled Popcorn.
Makes 12 cupcakes.