Key Lime Tarts

Creamy and sweet – yet lightly tart – it comes with the freshness of a cool breeze on a warm summer day. It’s not summer without a slice of a luscious key lime tart!

Key Lime Pie is probably one of the most popular and most recognized summer desserts. And there are many, many interpretations.

Some are just too cloyingly sweet but not this version. This offers a gentle balance of the clean, vibrant flavor of limes, sweetened just enough.

There is an abundance of lime flavor that comes from the juice of those tiny little green gems – and another layer of citrus with the addition of fresh lime zest.

Tucked into the whipped cream topping you’ll find rich, creamy mascarpone cheese with a touch of sweetness from powdered sugar. Highlight all three with a splash of pure vanilla extract and a dash of pure lime oil – adding one more note to accent that tart, little fruit.

Everything is piled onto a buttery graham cracker crust – simple, but oh, so wonderful!

Some notes on the Key Lime Tarts. If you can’t find key limes in the market you can certainly use Persian limes, which are more commonly found. They are a bit more tart than key limes so you can adjust the amount of lime juice to suit your taste.

This recipe will make two tarts but can easily be divided in half if desired. It takes quite a few little limes to get the zest and juice you need. A good juicer makes juicing citrus much faster – Breville makes a number of great options. For zesting, a microplane is a great kitchen tool to have on hand.

I often add mascarpone cheese to whipped cream. It adds some body to the cream and it seems to hold up better in the heat or when you need to transport a dessert. I always add a splash of pure vanilla extract to whipped cream for some depth. And for this dessert I also added a dash of pure lime oil for one more subtle hint of lime.

Go grab a big bag of key limes and get ready to bite into a cool bit of summer fun!

Key Lime Tarts

For the crust:

2-½ cups graham cracker crumbs

6 tablespoons sugar

10 tablespoons butter, melted

For the key lime filling:

2 cans sweetened condensed milk, 14-ounces each

8 extra-large egg yolks, with 2 egg whites reserved

1-¼ cup lime juice, preferably from key limes – about 40 key limes

2 tablespoons lime zest – about 14 to 16 key limes

For the whipped cream topping:

2 cups heavy cream

½ cup mascarpone cheese

½ cup powdered sugar

1 teaspoon pure vanilla extract

½ teaspoon lime oil*, optional

Whisk the graham crackers with the sugar. Add the melted butter and stir until well blended.

Divide the graham cracker mix between two 9-inch tart pans or two 14-inch by 4-inch rectangular tart pans. Use two piece tart pans so you can easily remove the tarts when finished. You can also use 9-inch pie plates.

Press the graham crackers into the bottom and sides of the pans. Place the tart pans on a rimmed baking sheet and bake in a 350-degree oven for 10 minutes.

While the crusts are baking make the key lime filling. Pour the sweetened condensed milk into a large mixing bowl. Add the egg yolks and whisk to blend together.

Add the lime juice and the lime zest.

In a small bowl beat the 2 reserved egg whites on medium speed until stiff peaks form, about 1 to 2 minutes.

Gently fold the egg whites into the key lime filling.

Divide the filling between the tart pans. Bake the tarts at the same temperature, 350-degrees for 15 minutes.

Allow the tarts to cool completely on a wire rack then chill for at least 8 hours. Leave the tarts in the pans.

To finish the tarts, pour the heavy cream into a mixing bowl. Beat on medium speed for about two minutes, just until the cream begins to thicken slightly. Add the powdered sugar, the mascarpone cheese, vanilla extra and lime oil. Continue beating the cream on medium-high speed until stiff peaks form.

Divide the whipped cream between the chilled tarts, spreading almost to the edges.

When you’re ready to serve, gently remove the tart from the pan by pushing up from the bottom to separate the bottom from the rim of the pan. Slide a thin metal spatula in between the tart and the bottom of the pan then gently slide the tart onto a platter.

Serve well chilled. Makes two 14-inch by 4-inch or two 9-inch round tarts.

* Citrus oils can be found at specialty cooking stores and online.