Preheat the oven to 180°C and line a 34 cm x 24 cm baking tin with greaseproof paper overlapping two of the sides so you can use the paper to lift the cake out of the tin.
In a large bowl mix together all the dry ingredients including the raisins. Make a well in the middle and add the almond milk, yoghurt, vanilla and chopped apple. Mix well and then pour into the baking tin, smoothing the top.
Finely slice the two apples for the topping and layer on top of the mixture. Overlap slices of the apple and lay some diagonally and some vertically so that you create a nice pattern.
To make the crumble, mix together the chopped pecan nuts, flour and maple syrup. It should be lumpy. Scatter this over the top, leaving some slices of apple uncovered. If you dip the slices of apple in lemon juice before you lay them on the top it will prevent them from browning in the oven.
Bake for 30 minutes or until a skewer inserted in the middle comes out clean. Then cool in the tin for a few minutes before transferring to a wire rack to finish cooling.
Cut into 12 squares.