Mojitos are one of my favorite summertime drinks. Made with rum, lime and mint – and occasionally with other fruits, as well – they are an incredibly refreshing happy hour option on a hot day. These Mojito Shortbread Bars are a twist on a traditional lemon bar, with a mint, rum and lime filling sitting atop a buttery shortbread base.
The filling starts with lots of fresh lime juice, along with sugar and eggs. Since mojitos typically involve smashing fresh mint into the bottom of a cocktail glass along with fresh lime, the filling also includes mint. Fresh mint – peppermint is typically used, not spearmint – didn’t impart quite the flavor that I wanted (either too much or too little), so I found it easier to work with peppermint extract. You only need a few drops to get enough mint flavor, so when you are measuring be careful not to accidentally overflow the measuring spoon!
I also added a splash of rum to the filling, but not enough to overpower the other ingredients. If you prefer to make your bars alcohol-free, you can replace the rum with a little bit more lime juice. Rum or not, you should use only fresh lime juice in this recipe to ensure that you get the best results.
The bars use my favorite style of shortbread base, which is baked and has the filling poured onto it while it is still hot. The shortbread has a great flavor and bakes up enough during its initial time in the oven to stay crisp and tender, even as the lime custard mixture above it sets. I added a bit of lime zest to the mixture of butter, flour, sugar and salt to better tie the base in with the filling. To be honest, you can also make the base and eat it alone, as lime shortbread is pretty tasty even without the mojito filling!
These need to set up in the refrigerator before you can slice them, so be sure to make them several hours ahead of when you intend to serve them. The recipe makes enough for a crowd, making these an excellent choice for a party or other gathering. Leftovers can be stored in the refrigerator and will last for a few days. Dust the bars with confectioners’ sugar to serve.
Mojito Shortbread Bars
1 1/2 cups all purpose flour
1/3 cup sugar
2 tsp lime zest
1/4 tsp salt
1/2 cup butter, room temperature
4 large eggs
1 1/2 cups sugar
1 cup minus 2 tbsp freshly squeezed and strained lime juice
2 tbsp white rum
1/4 tsp peppermint extract
Preheat oven to 350F. Line 9 x 13-inch baking pan with aluminum foil.
Make the crust. In a large bowl, whisk together flour, sugar, lime zest and salt. Add softened butter and blend in with an electric mixer at low speed until mixture forms coarse, sandy crumbs. Pour into pan and press mixture firmly down (with your fingers or the back of a spoon) into an even layer.
Bake for 16-19 minutes, until just lightly browned around the edges.
Make the filling. When the crust is just finished baking, or has only one minute to go in the oven. whisk together all filling ingredients in a large bowl until well-combined, about 1 minute. Pour filling mixture into the hot crust and immediately return to the oven.
Bake for about 20 minutes, or until filling is just barely set (it will still jiggle when the pan is moved and may begin to turn a very light brown on top).
Cool completely and refrigerate for at least 1 hour before slicing.
Top slices with confectioners’ sugar to serve.
Makes about 20 bars.