Preheat oven to 350°F and line 24 cupcake cups with paper liners.
Place cake mix, pudding mix, oil, milk, eggs, vodka, 1/4 cup Kahlua, and vanilla in a large mixing bowl.
Blend with an electric mixer on low speed for 30 seconds. Stop the machine and scrape down the sides of the bowl. Increase the mixer speed to medium and beat 2 minutes more, scraping down the sides again if needed.
Spoon or scoop 1/3 cup batter into each lined cupcake cup, filling it three quarters of the way full. (Remove empty liners if you don't get the full 24 cupcakes).
Bake until they are golden and spring back when lightly pressed with your finger, about 17-20 minutes. Remove the pans from the oven and place them on wire racks.
Cool for 5 minutes. Brush the tops of the cupcakes with remaining 2 tablespoons Kahlua.
Remove cupcakes from pans. Place on wire rack to cool.
Place a large, clean mixing bowl and electric mixer beaters int he freezer to chill for 1 minute. Remove the bowl and beaters from the freezer.
Pour the heavy cream into the bowl and beat with electric mixer on high speed until the cream has thickened, 1 1/2 minutes.
Stop the machine and add the sugar and 1 tablespoon Kahlua.
Beat the cream on high speed until stiff peaks form, 1-2 more minutes.
Place a heaping tablespoon of the whipped cream on each cupcake and swirl to spread it out with a short metal spatula or spoon, taking care to cover tops completely.