Preheat oven to 350*F. Prepare 9x13 glass baking dish with unbleached parchment paper
Mill the grains. Add flour, sugar and salt to a bowl (stand mixer with paddle attachment) to combine.
Add softened butter. Mix until crumbles form.
Set aside 1 cup of crumbles.
Press the remainder of the shortbread into the prepared 9x13 dish.
Bake for 15 mins.
Add pie filling and spread evenly. Sprinkle your 1 cup of crumbles onto the pie filling.
Continue baking for 30-40 mins. It could take longer depending on the grain as some whole grains are denser and seem to need more baking time!
Allow the bars to COOL COMPLETELY before cutting and eating. I know. It’s hard. But pop it in the fridge if you need to.