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Thin Mint Key Lime Tart Recipe -- A minty Key lime custard in a Girl Scout Thin Mint cookie crust. This fresh, creamy dessert is beautiful, unique and oh-so-tasty!

Thin Mint Key Lime Tart Recipe

The mint flavor with the fresh lime is bright and lovely, and comes to you in an incredibly creamy, rich custard that rests in a crisp crust made from Thin Mints. It's a perfect blend of flavors and textures.

*Please note that about 4 1/2 hours of the prep time is refrigeration time.

Course Dessert
Cuisine American
Keyword citrus pies and tarts, citrus desserts for a party, recipes using Thin Mints
Prep Time 4 hours 40 minutes
Cook Time 20 minutes
Total Time 5 hours
Servings 8
Calories 254 kcal
Author Valentina K. Wein


For the crust

  • 1 1/4 boxes Thin Mints Girl Scouts cookies (2 dozen cookies)
  • 6 tablespoons unsalted butter, melted

For the filling

  • 8 ounces cream cheese, softened
  • 3/4 cup granulated sugar
  • zest of 2 Key limes
  • 3 tablespoons Key lime juice, from about 5 Key limes
  • 2 tablespoons green Crème de Menthe
  • 6 large eggs

For the garnish

  • 1 tablespoon Thin Mints Girl Scouts cookies, finely ground (saved from above)
  • a few thin Key lime slices
  • a few small mint leaves


  1. Add the Thin Mints to a food processor fitted with the blade attachment. Pulse until they’re a fine powder. Remove 1 tablespoon and set it aside for garnish. Then add the rest to a medium-sized mixing bowl and stir in the melted butter. Mix until it’s evenly blended. Then using your hands, evenly press the mixture into a 9 1/2-inch tart pan with a removable bottom. Set aside.
  2. In a large, heat proof, medium-sized mixing bowl (stainless steel is great), whisk the cream cheese with the sugar. It’s best to use an electric mixer — for the smoothest possible result. Add the Key lime zest and juice, and Crème de Menthe. Mix again until smooth. Then, gradually add the eggs, one at a time, mixing between each addition.
  3. Place the bowl over a pot it fits snugly into, with a couple of inches of water in it. (Be sure the bottom of the bowl doesn’t touch the water.) Turn the heat to medium and whisking almost constantly, cook until the mixture is creamy and thick, like custard. This should take about 20 minutes. Remove it from the heat and let it cool to room temperature.
  4. Pour the cooled custard into the prepared tart crust and place in the refrigerator for at least 4 hours.

  5. Sprinkle the reserved 1 tablespoon on top and add a few Key lime slices and mint leaves. Place the tart in the freezer for 30 minutes before slicing — it will be easier to cut this way.