To Make the crumble
Grease and line a brownie tin or rectangular cake tin roughly 23 x 33 cm
Preheat oven to 180oC
Combine all the dry ingredients in a bowl and pour over the melted butter.
Mix well to from a crumble.
Divide the crumble mixture in two and press the first half firmly into the tin, spreading evenly and into the corners, smooth with the back of a spoon.
Spread the roasted plums evenly over the base, and top with the second half of the crumble mixture, press down lightly with a flat palm, and sprinkle over the chopped pistachio nuts
Bake for 30 - 40 minutes until golden brown.
Remove from the oven and allow to cool completely in the tin before removing from the tiin. If you can wait I find that if it stands for 24 hours the bars cut better and don’t crumble and fall apart.
Serve sifted with icing sugar or drizzle with lemon plum icing.
To make the icing
stir lemon juice, lemon zest and plum syrup into icing sugar and mix until desired consistency.