Preheat the oven to 350 F (180C). Dice the chayote into small pieces. Add ⅓ cup of powdered sweetener, cinnamon, ground cardamom, lemon juice, vanilla extract, gelatin, and ⅛ tsp kosher salt. Mix well with a spoon. Pour the mixture into a small casserole dish.
Step 2
In a small food processor, crush the pecans to a fine crumble. You want to make sure the crumble is fine, but not a powder. The size of the finished crumble should be about the size of a peppercorn. Then transfer the crumble to a bowl and combine it with the remaining sweetener, salt, and softened butter.
Step 3
Add the crumble on top of the diced spiced chayote. Bake 20-25 minutes or until the top is nicely golden brown. Allow the crisp to cool so the gelatin will thicken the fruit slightly.
Step 4
The filling will thicken as the crisp cools. Serve warm with Keto vanilla ice cream, if desired. The crisp will last in the fridge for up to three days.