First, make your sugar-free sweetened condensed milk according to its specific recipe. It's important to let it cool completely to room temperature for the best results in your pie filling.
Preheat your oven to a cozy 350°F (176°C). While the oven warms up, prepare your chosen keto pie crust as instructed in its recipe, then set it aside to cool. Keep that oven on, as it'll be ready for your pie soon!
In a medium-sized mixing bowl, combine the cooled condensed milk, the four egg yolks, and a tiny pinch of sea salt. Grab a whisk (or an electric mixer) and blend these ingredients until the mixture is beautifully smooth and evenly combined.
Now for the star of the show! Pour in the refreshing key lime juice and stir in the fragrant lime zest. Continue whisking until these vibrant flavors are fully incorporated into your creamy base.
Give your lime filling a little taste test. If you desire a bit more sweetness, gradually whisk in the Besti Powdered Monk Fruit Allulose Blend until it reaches your preferred level of sweetness and is completely dissolved, ensuring a smooth texture.
Carefully pour the luscious lime filling into your prepared and cooled pie crust. Gently smooth the top with a spoon or spatula. To protect the edges of your crust from browning too quickly, cover them with a strip of aluminum foil or a pie shield.
Place your assembled keto key lime pie into the preheated oven and bake for just 15 minutes. Don't be alarmed if the center still looks a bit runny – this is perfectly normal and expected! The filling will set as it chills.
Once baked, remove the pie from the oven and let it cool on your kitchen counter for a good 30 minutes. After this initial cooling, transfer the pie to the refrigerator. It needs at least 3 to 4 hours (or ideally, overnight) to chill completely and achieve that perfect, firm, and creamy consistency.
Once your pie is perfectly set and chilled, it's ready to enjoy! Slice it with a sharp knife, wiping the knife clean between cuts for tidy slices. For an extra touch of elegance and flavor, top each slice with a dollop of sugar-free whipped cream and a thin slice of fresh lime.