While the photo does not do them justice (they were sliced into mini bite-sized squares for the dessert table and as a result got a little squished), I proudly stand by this little recipe, and hope you will give this a try the next time key limes are in season! Original recipe courtesy of Martha Stewart's food website.
*My personal recommendation would be to make these as bite-size individual tarts, using a mini-muffin pan (I wish I had thought of that in time for my wedding!)*
Key Lime Bars
If you can't find Key limes or don't wish to zest and juice 2 dozen teeny-tiny little limes, you can use regular fresh lime juice. Won't be as amazingly good as with Key limes, but probably still quite tasty.
YIELD: Makes about 16 regular size bars (2"x2")
1 cup plus 2 1/2 tablespoons finely ground graham cracker crumbs
1/3 cup granulated sugar
5 tbsp. unsalted butter, melted
3 large egg yolks, room temperature
1 1/2 tsp. finely grated lime zest
2/3 cup fresh Key lime juice (about 22-24 Key limes)
1 tin sweetened condensed milk (14 ounces)
1/4 cup heavy cream, kept refrigerated until needed
2 Key limes, thinly sliced into half-moons
Make crust: Preheat oven to 350 degrees F. Stir together graham cracker crumbs, sugar, and butter in a small bowl. Press evenly onto bottom of an 8-inch square glass baking dish. Bake until dry and golden brown, about 10 minutes. Let cool completely on a wire rack. (Leave oven on.)
Make filling: Put egg yolks and lime zest in the bowl of an electric mixer fitted with the whisk attachment. Mix on high speed until very thick, about 5 minutes. Reduce speed to medium. Add condensed milk in a slow, steady stream, mixing constantly. Raise speed to high; mix until thick, about 3 minutes. Reduce speed to low. Add lime juice; mix until just combined.
Spread filling evenly over crust using a spatula. Bake, rotating dish halfway through, until filling is just set, about 10 minutes. Let cool completely on a wire rack. Refrigerate at least 4 hours or overnight.
Carefully lever entire block onto clean cutting surface and cut into 2-by-2-inch bars*. Pour cold cream into the clean bowl of an electric mixer fitted with a clean and dry whisk attachment (for a rapid whip, it is recommended to refrigerate/freeze your bowl and whisk attachment for at least 1/2 hour prior to whipping the cream). Mix on medium-high speed until stiff peaks form. This can also be done by hand.
Garnish bars with a whipped cream rosette and a thin half slice of lime.
*When cutting bars, be sure to use a long, sharp knife, dipped frequently in hot water and wiped clean before every cut.
Baker's Note: Ungarnished bars can be refrigerated in an airtight container up to 3 days.