Preheat the oven to 350°F. Lightly spray a 9-inch, deep pie plate with cooking spray.
In the bowl of your food processor, combine the graham crackers and 1∕3 cup of the sugar and pulse until crushed. Stir in the melted butter until well blended. Press the cracker mixture onto the bottom and up the sides of the pie plate. Bake until firm, approximately 8 minutes.
In a stand mixer fitted with the paddle attachment , beat the condensed milk, egg yolks, lemon juice, and salt on medium speed for 4 minutes.
Pour the mixture into the baked pie crust. Return to the oven and bake until the center is set when the pan is gently wiggled, about 10 minutes.
Cool the pie on a wire rack for half an hour. Place in the refrigerator until set, at least 1 hour and up to 3 days. This is a great pie for making ahead!
Make the whipped cream topping when ready to serve the pie. In the bowl of your mixer, fitted with the whisk attachment, beat the cream, sugar, and vanilla on high speed until fluffy and the cream holds a soft peak when you pull the beater out of the bowl.
Spread the cream on the cooled pie. Garnish with a fresh lemon twist, a sprinkle of lemon zest, and a mint sprig.
Store leftover pie in the fridge.