Preheat the oven to 320°F (160°C).

Soak the dates in the one cup warm water for about 10 mins. Place them in a food processor and pulse until a smooth mixture is formed. You may need to add just a little water, to go easier. Save the water from the dates.

In a large bowl combine the whole wheat flour, oats, cinnamon, cardamom, vanilla, and ground walnuts. 

Mix the baking soda and apple cider vinegar in a small bowl. Then add them to the dry ingredients, together with the water from the dates, the chopped dates, and shredded apple.

Mix everything well with a spoon until a sticky dough is formed. Set aside for 10 mins.

Line a 6 x 8-inch baking pan with parchment paper. Press the dough evenly into the pan and bake for about 35 mins.

Optional: for the topping, put the thawed raspberries in a food processor with three tablespoons of water until finely chopped.

When the Oats Apple Cake is ready, allow it to cool on a baking rack before cutting.

Then cut it into 12 bars and top with the raspberry topping. Sprinkle with some fine oats and enjoy!