Serves 50 Fruit layer: 6 quarts fresh peaches 3 quarts blackberries 3 quarts blueberries 1 cup sugar, or more if fruit is not very sweet 1 cup all-purpose flour 1 tbsp cinnamon 1 tbsp almond extract (optional)
Crumble topping: 1 cup all-purpose flour 1 cup whole wheat flour 2 cups oats 2 cups brown sugar 1/2 tbsp kosher salt 1/2 cup (1 stick) butter, melted 1/2 cup vegetable oil
Preheat oven to 350 degrees.
To make fruit layer, combine fruit, 1 cup sugar, 1 cup flour, cinnamon, and almond extract, and spread into 2 full-size catering pans (approx. 10×18 size pans). Combine all-purpose flour, whole wheat flour, oats, brown sugar, and salt in large bowl. Pour melted butter and oil over dry ingredients and mix with your hands to combine. Sprinkle topping over fruit layer and bake for 45-50 minutes, or until crumble is golden brown and bubbly.