Place the flour, porridge, brown sugar, caster sugar, butter in a large bowl and mix well to combine. Press half the crumble mixture into the base of the traybake.
Add the berries then top with the rest of crumble mixture and bake in the oven for 35–40 minutes or until golden brown.
Remove from the oven and allow to cool in the traybake.
Dust with icing sugar and cut into slices. Enjoy within a few days and store in a thigh container in the fridge.
Keyword afternoon tea, berries, Cake, quick and easy