In a food processor, grind the walnuts to a fine crumb texture and pour into a large bowl.
Add the oats to the processor and pulse until the texture is in between whole oat and flour texture then add to walnuts.
Add the flour, sugar, coriander and salt then mix well.
Add 1/4 pieces of butter and mix everything with your hands until it is a crumbly consistency.
Put in the refrigerator while you make the shortbread so the butter can harden.
Shortbread
Preheat oven to 350 degrees.
Make sure the butter is at room temperature.
Cream butter, sugar and pinch of salt in food processor or mixer until creamy then add flour and pulse until it’s mixed well.
Pour out mixture into a 9″ by 14″ baking dish and press the dough evenly around.
Poke holes all over with a fork to prevent bubbles.
Bake for 15 to 20 minutes or until edges are golden.
Jam
While the shortbread is baking, start the jam.
In a large saucepan, bring persimmon puree, sugar and lemon juice to a boil on medium high then turn to medium heat for 10 minutes. Stir frequently.
Lower heat and simmer for 15 – 25 minutes until persimmons are dissolved and reduced.
In a small bowl, combine arrowroot powder and rose water together.
Add arrowroot/rosewater mix stirring continuously until well incorporated
Remove from heat. Set aside
Rose powder
If using whole dried roses, remove the petals, measure and grind in a coffee or herb grinder until it becomes a fine powder.
Assemble
Preheat oven to 375 degrees.
Spread the jam evenly over the baked shortbread and then evenly sprinkle with the crumble, lightly press down and bake for 15 to 20 minutes or until golden.
Cool completely before cutting and removing from the pan.