500 grams (about 4 cups) AP Flour
500 grams (about 2 ½ cups) Sugar
350 grams (4 cups) Oats
10 grams (about 2 tsp) Salt
5 grams (about 1 tsp) Baking Powder
5 grams (about 1 tsp) Baking Soda
5 grams (about 2 tsp) Cinnamon
450 grams (about 2 cups) Butter, cold and cubed
Lemon zest - 2 each
900 grams (about 30 oz) Raspberries
200 grams (about 1 cup) Sugar
30 grams (about ¼ cup) Cornstarch
30 grams (about 1 oz) Lemon juice
Mix all of the oat crumble ingredients together in a mixer with a paddle attachment until crumbly. Spread two thirds of the crumble on to a parchment lined half sheet tray. Lightly press crumble into pan and bake at 350˚F until lightly golden brown, between 10-15 minutes. Meanwhile, put all of the raspberry filling ingredients in a mixing bowl and mix with a paddle attachment until cohesive. Pour on to baked crumble and sprinkle with the rest of the raw crumble mixture. Bake at 350˚F until raspberry filling is thickened and bubbling along sides of pan and crumble topping is golden brown.
Let cool, then cut into preferred shape. For best results freeze bars for 30 minutes before cutting.