Line a large baking dish with greased paper and set aside. In large microwave safe bowl, combine the flour, protein powder, granulated sweetener and Saigon cinnamon and mix well. In a microwave safe bowl, combine the nut butter and liquid sweetener and heat until melted. Add the vanilla extract and pour the wet mixture into the dry and mix well- It should be crumbly. Using a spoon, add the dairy free milk of choice one spoonful at a time until a thick, firm batter is formed. Transfer to lined baking dish and press firmly. Rub the cinnamon bun topping on it and refrigerate for at least 30 minutes.