Add crust ingredients to a food processor and pulse until very fine.
Press mixture into the bottom of a 22 x 12 centimeter loaf pan. I recommend lining with parchment paper. It makes getting the bars out easier.
Place in the freezer whilst you prepare the filling. Clean out the processor to use for the filling.
Rinse and drain the water from the soaked cashews.
Add cashews to food processor, along with lemon juice, coconut oil, maple syrup, and lemon zest. Blend until creamy. You can add one to two tablespoons of water if needed to achieve a creamy consistency.
Pour filling onto the crust and using a spatula, spread across the pan evenly. Place in the freezer whilst you prepare the raspberry topping.
Blend the raspberries and lemon juice, and add them to a small pan on medium heat. Stir in the agar agar. Bring to a slight simmer and remove the pan from the heat.
Pour the raspberry topping over the cashew filling. Cool for 15 minutes and place in the freezer for two to three hours, or until the mixture has firmed.
Allow to thaw for 10-15 minutes. If you used parchment paper, use a knife to separate the bars from the edge of the pan. Pick up the bars using both sides of the parchment paper.