Preheat oven to 375°F. Lightly spray a 9-inch pie dish or 10-inch deep pie dish with cooking spray.
Crust: In a small bowl, stir together the graham cracker crumbs, sugar, almonds and butter Press crumb mixture into pie dish. Bake for 8 minutes just until lightly golden brown. Cool completely.
Key Lime Filling: Preheat oven to 325°F Using an electric mixer, whip together egg yolks on high speed until fluffy and thickened, around 3-5 minutes.
Gradually add condensed milk and lime juice. Add sour cream, zest and vanilla on low speed, mixing until fully combined.
Pour the filling into baked graham cracker crust and smooth the top.
Bake for 30 minutes or until the center is set when gently shaken. Let pie cool at room temperature slightly before chilling. Chill for at least 4-6 hours.
Decorate the top of the chilled pie with swirls of Cool Whip or whipped cream and sprinkle the top with additional lime zest.
How to Make Whipped Cream:Place a large bowl and beaters into the freezer for 15-20 minutes to chill. Once chilled, add one pint or two cups of heavy cream and 1-2 teaspoons of pure vanilla extract to the bowl.Using an electric mixer, beat on medium-high speed gradually adding 1/4-1/3 cup of granulated sugar. You can adapt the sweetness to your taste. Beat until stiff peaks form being careful not to overbeat. then chill until serving. Fresh whipped cream is best made and served the same day.
Notes
Lime Juice - It takes a good amount of elbow grease to squeeze enough key limes for juice. If you're not up to the challenge feel free to swap out with the more common limes we use everyday. Expect the pie to be slightly more acidic should you choose to do so.
Key Lime Juice Substitution - You can use equal parts of regular lime juice and fresh lemon juice to mimic the taste of key limes.
Sugar - You can use brown sugar in place of granulated sugar for the crust.
Color - While key lime juice isn't green, you may choose to use a few drops of green food coloring to change the hue of the key lime filling, if you're so inclined. It won't affect the taste, it's simply visual, so it's your choice to make. As you can see in the images of the recipe, I like the pale yellow color and serve it naturally that way.
Whipped Cream - You can garnish this pie using Cool Whip or fresh whipped cream. Fresh whipped cream should be added the day you plan on serving the pie.
Alternate Topping - You can either freeze the leftover egg whites or turn them into a meringue topping for the key lime pie.