Crush the Gluten-Free Cinnamon Chex cereal in a food processor until you have 1 ½ cups. It takes 3 cups of cereal to make 1 ½ cups.
Add the Gluten-free Bisquick and chopped unsalted butter to the food processor. Process until the consistency of thick sand.
Pour the Chex mixture into a medium-sized bowl. Add the ice water and mix with your hands until the dough starts to stick together.
Spray a 9-inch pie dish with gluten-free cooking spray. I like gluten-free coconut oil spray.
Press the Chex crust mixture into the bottom of a greased 9-inch pie pan and slightly up the sides. Press down in the pan to make sure it is tight and compact. I use the bottom of a flat measuring cup to help press the mixture down.
Bake the pie crust on the middle rack for 8 minutes. Allow the crust to cool.
Key Lime Filling
In a large bowl, whisk the egg yolks together until fully combined.
Add the pure vanilla extract and the two cans of sweetened condensed milk to the whisked egg yolks. Mix until fully combined and creamy.
Stir in the key lime juice and mix until fully combined and creamy.
Pour the key lime filling into the cooled crust. Smooth the top of the pie with a spatula.
Using the middle rack, bake for 20 minutes.
Let the pie cool at room temperature for 30 minutes, then place in the refrigerator to chill thoroughly - about 3 hours.
Serve topped with whipped cream. Enjoy!
Cover the leftover pie with plastic wrap and refrigerate.