From the blog For Love of the Table
1 1/2 c. sugar
1 t. lime zest
3/4 c. strained key lime juice (this will take about 1 lb. of limes)
4 eggs
4 oz. (1 stick) unsalted butter, cut into pieces
1 9-inch pre-baked graham cracker crust (see below)
1 1/2 c. whipping cream
3 T. sugar
3/4 t. vanilla
Combine the sugar, zest and key lime juice in a medium saucepan and bring to a boil over high heat. In a medium-sized bowl, whisk the eggs until homogenous. When the syrup boils, whisk it into the eggs in a thin stream. Return this mixture to the saucepan and place over medium heat. Stir constantly until the mixture is visibly thickened—this will only take about 3 minutes. Remove from the heat and whisk in the butter, piece by piece.
When the butter is fully incorporated, strain the curd into the graham cracker crust. Place on a baking sheet and bake in a 350° oven until set (it will still be a bit wobbly, but it won't be liquid-y)—15 to 20 minutes. Let the tart cool before transferring to the refrigerator to chill until cold.
Combine the whipping cream, sugar and vanilla. Whip until soft peaks form. Swirl over the tart.
Chill for an hour or so. Sprinkle some of the reserved crumbs over . Cut into wedges and serve. Serves 8 to 10.
(Recipe adapted from Emily Luchetti's Four Start Desserts)
Graham Cracker Crust:
1 1/4 c. (120 g) graham cracker crumbs
1/4 c. sugar
1/2 t. cinnamon
2 oz. (4 T.) unsalted butter, melted
Combine dry ingredients. Add the melted butter, stirring until the mixture is homogenous. Set aside 2 Tablespoons of the crumbs. Press the remaining crumbs into a greased, removable-bottom 9-inch tart pan, covering the sides and the bottom evenly. Bake in a pre-heated 350° oven until beginning to brown—10 to 12 minutes. Set aside.