Preheat oven to 375° F. In a bowl, whisk together flour, salt and baking powder. Set aside. In a separate small dish, combine apple cider vinegar, milk and baking soda. Stir to combine. Mixture will foam up a bit.
In a stand mixer fitted with a paddle attachment, cream butter, vanilla, and sugar together. Add bourbon and egg whites. Mix briefly to combine.
With the mixer on low, add one-third of the flour mixture to the batter. Then add half of the milk mixture. Repeat and end with remaining flour. Mix batter until everything is just combined.
Scoop batter into each liner until it’s about two-thirds of the way full. Bake cupcakes for 12-15 minutes until a toothpick comes out clean.
Meanwhile, make the frosting. Cream butter, vanilla extract, bourbon together in a clean stand mixer bowl. Add bourbon, maple syrup and one tablespoon milk to bowl and mix briefly to combine.
Add powdered sugar to bowl one cup at a time, mixing on low speed between each addition. Mix until the frosting is fluffy. Add more milk as needed for a thinner texture.
Transfer the frosting to a piping bag and frost the cooled cupcakes. Sprinkle with cooked pieces of bacon.