Key Lime Pie was originated in the Florida Keys where many key limes are grown and tend to be smaller in size than regular limes and are known to have a slightly sweeter and bitter flavor. Key limes are usually harvested too soon, when they are green in color, but key limes should be picked when they are yellow for maximum sweetness. In my recipe for Key Lime Pie with Mascarpone Whipped Cream, I use the limes off my tree in the backyard, which tend to have a nice balance of sugar and acid and I harvest them mostly when they are yellow, just by accident because I have so many.
Many key lime pie recipes have a meringue topping, but I love this pie with a refreshing mascarpone cream. Mascarpone cream is an Italian cream cheese and tends to have a more mild flavor than American cream cheese, which pairs nicely with the lime filling. I make a traditional no-fuss graham cracker crust for the bottom layer and the rest is pretty simple.
1 package graham crackers, about 14 crackers
2 tablespoon sugar
6 tablespoon melted butter
4 egg yolks
14 ounce can sweetened condensed milk
1/2 cup lime juice
1 1/2 cup heavy cream
4 ounce mascarpone cream
2 tablespoons confectioners sugar
zest of 1 lime
(Makes 1 Pie)
1. Preheat the oven to 350 degrees. In a food processor, add all the crust ingredients and pulse until coarse crumbs. Pour the crumbs into a 9-inch pie pan and press in the bottom and sides, using a measuring cup.
2. Put the crust in the oven to bake for 10 minutes. While the crust is baking, prepare the filling by adding the egg yolks and sweetened condensed milk to a bowl. Then, pour in the lime juice with the egg mixture and whisk until smooth.
3. When the pie crust has cooled for 5 minutes, pour the filling into the crust and bake again for 15-20 or until just set. Remove the pie from the oven and let cool to room temperature. Place the pie in the refrigerator to chill for 2 hours before making the topping.
4. In a stand mixer or in a large bowl with a hand mixer, add the heavy cream and whip until frothy, about 3 minutes. Then, add the mascarpone cream and confectioners sugar, whip again until soft peaks are formed. Do not over whip.
5. Dollop the cream on the center of the pie and using a offset spatula, smooth out the cream over the entire pie.
6. Sprinkle the zest over the top of the pie (I found a green one) and serve immediately or refrigerate until ready to eat. Enjoy!