Graham Cracker Crust: Preheat the oven to 375F. In a food processor, pulse the graham crackers until they are fine crumbs. Mix the graham cracker crumbs, granulated sugar and melted butter together. Press the mixture into a 9” pie dish. Make sure the crust covers the bottom of the dish and goes up most of the way on the sides as well. Use a measuring cup with a flat base to pack the crumbs down tightly. Bake the empty pie crust for 8-10 minutes. Remove the crust from the oven and let it cool for about 10 minutes before adding the key lime pie filling. Reduce the oven temperature to 350F. 

Key Lime Pie Filling: In a large bowl, mix the sweetened condensed milk, cream, egg yolks and key lime juice together. Pour the filling into the warm pie crust. Bake for 18-22 minutes until the filling is mostly fully set, and only slightly jiggly. Remove the pie from the oven and let it cool to room temperature. Then, refrigerate the pie for at least 3 hours before serving.

Whipped Cream Topping: With an electric mixer, beat the cream and icing sugar together until soft peaks form. Serve the pie with a dollop of whipped cream.