Preheat the oven to 350 F and line two cupcake pans with 15 cupcake liners total.
In a large bowl (not your mixing bowl) add the cake flour, baking soda, baking powder, lime zest, and salt. Mix until combined then set aside.
In your mixing bowl, add your softened butter and granulated sugar. Beat on a medium speed for about 3 minutes until pale and fluffy.
Add the eggs to the mixing bowl and beat on medium speed for another 2-3 minutes until light and fluffy.
Scrape down the edges of the bowl, then add your sour cream. Mix on a low speed until sour cream is thoroughly incorporated.
Add dry ingredient mixture to the mixing bowl. Use a spatula to gently fold in some of the dry mixture so that it doesn't fly out of the bowl when you turn on the mixer. Mix on low speed until just barely combined. Do not overmix!!
With the mixer running on a low speed, slowly pour in gin, tonic water, and lime juice into the bowl. Mix until just combined. Use a rubber spatula to scrape down the sides and bottom of the bowl to ensure everything is well mixed.
Fill the cupcake liners about 2/3rds of the way full. This is usually about 3 Tablespoons of batter.
Bake at 350 F for 15-18 minutes or until you can lightly touch the center and it springs back at you. Or, bake until a toothpick comes out clean when you poke the center of your cupcake. Mine usually take exactly 17 minutes, but everyone’s oven is different.
Let the cupcakes cool completely.
Use a fork to poke some holes about 4 times in each cupcake. Next, pour ¼ teaspoon of gin on top of each cupcake. For an extra boozy cupcake, increase this to ½ teaspoon. Any more than that could overpower the other flavors in the cupcake so beware of that before adding too much.