Cook the porridge as per usual or follow the link above. Let it rest.
Meanwhile, put the blackberries and stevia in a small saucepan. Add the lemon juice and vanilla essence and cook until you get a thick purée. Set aside in a small bowl. Clean out the pan.
Peel, core then dice the apple, then put these in the pan. Add the cinnamon, honey/maple syrup and cook until the apple has slightly caramelised. Set aside.
Spoon half of the porridge into two cups or bowls, then add a spoonful of the caramelised apple and some walnuts, followed by about two spoonfuls of vanilla yoghurt or custards, then some blackberry purée.
Repeat the layering.
You can finish it with some whipped (vegan) cream if you like, and garnish with a piece of walnut.
Serve warm or cold.