Chop rhubarb into bite sized pieces. Combine in medium bowl with vanilla, 2 tablespoons Pyure (or desired sweetener), and xanthan gum. Spread out into small casserole dish.
Topping
Combine almond flour, coconut flour and 1 tablespoon Pyure (or desired sweetener) in medium bowl. Blend in butter pieces using pastry cutter or fork. Sprinkle topping evenly on top of filling.
Baking/Serving
Bake at 350°F for 35-40 minutes or until top is golden. Serve warm. Can be topped with ice cream or whipped cream.
Notes
Any sugar replacement can be used for the sweetener. Sugar amount is provided for those who want gluten-free but not low-carb.Net Carbs per Serving: about 8g