Line a large baking dish with greased paper and set aside.
In large mixing bowl, combine the flour, protein powder, granulated sweetener, cinnamon, nutmeg and mixed spice and mix well.
In a microwave-safe bowl, combine the nut butter and liquid sweetener and heat until melted. Pour the wet mixture into the dry and mix well. Add the unsweetened applesauce and mix until combined- The batter 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. Refrigerate for at least 30 minutes.