I don't share my recipes with anyone who knows me personally. I posted the picture of these on Facebook after I finished making them and I got a bigger response on these than any other sweet treat I have ever made and posted. Let me know what you think of them.
**Addition** I sell my cupcakes and wouldn't do great business if I gave away all of the recipes that I invented. Granted, I don't use a boxed cake mix when I make mine for a paying customer, but it's easier for the home baker. Any of my non dessert recipes I am happy to give away and do so frequently.
Preheat the oven to 350 degrees. Prepare cupcake pans with cupcake papers, enough for 24 to 36 cupcakes.
CAKE: To a mixing bowl, add cake mix, eggs, oil, 2 teaspsoons lime zest, 1/4 cup lime juice and 1 cup of water. Mix according to package directions.
Portion a scant 1/4 cup of batter per cupcake liner. Bake for 15 to 20 minutes until done and when cupcake is touched in center, bounces back and doesn't leave an indentation. Remove to racks to cool.
While cupcakes bake, beat butter with paddle attachment of mixer until very smooth. Add powdered sugar and 2 teaspoons of lime zest; beat on slow speed. While mixer is running, mix together in a liquid measuring cup, 1/4 cup lime juice, 1 tablespoon tequila and 1 teaspoon Grand Marnier. Add 4 tablespoons of liquid mixture to the butter/powdered sugar mixture (1 Tablespoon at a time,) beating well between each addition. Once all 4 tablespoons are added, beat on medium-high speed for about 5 minutes. Then let your mixer run at low speed until you are ready to use the frosting. This keeps the frosting from getting crusty.
By this time, the cupcakes should have come out of the oven. While the cupcakes are cooling, to the remaining lime/tequila mixture that you used to make the frosting, add 1 more tablespoon of tequila and 1 teaspoon of Grand Marnier. If you need or want to add a little more lime juice, feel free. Use a pure bristle pastry/paint brush and brush each cupcake with this juice mixture. Once you have brushed each cupcake, brush each one again. Then brush each cupcake one last time. (That is a total of three brushes for each cupcake.) The liquid should have time to soak in between brushings.
Now that the cupcakes are brushed and cooled, frost the cupcakes. Using a piping bag with a 1M star tip is quick and easy and makes them look like you got them from a bakery. Once frosted, sprinkle with fresh lime zest and serve.
DISCLAIMER: Hopefully this doesn't need to be said, but... Don't forget that these cupcakes have liquor in them, so they are not appropriate for children or anyone under the age of 21 years.