Preheat the oven to 300F, Mix crunch mixture together
In a food processor, combine the carbalose flour, shredded coconut, chopped pecans, sweetener, cinnamon, and salt. Pulse a few times to combine. Sprinkle with butter pieces and blend with a pastry blender until the mixture resembles coarse crumbs.
Put 1/2 crumbly mixture in bottom of 9inch greased pan, press down firmly with your hands so that the mixture sticks together. Bake for about 15 minutes or until golden.
Rhubarb Filling
Add sugar mixture ingredients to saucepan. cook till clear
Place 6 cups of rhubarb on top of crumbs. Pour sauce over rhubarb mixture. Top with remaining crumbs. Bake about 1 hour 350* top with keto Ice cream or whipped cream