Makes 12 big bars or 16 little bars

You can swap the blackberries or mulberries for one another and use all one berry type or try this recipe with raspberries, strawberries, blueberries, red currants or even rhubarb! Mix and match whatever berries you have on hand or to your taste preferences.

Preheat the oven to 375°F. Grease an 8×8 or 11×7-inch cake pan and set aside.

Berry Layer

1.5 cups fresh blackberries
1.5 cups fresh red mulberries 
1/2 cup sugar (coconut or white)
1 tablespoon arrowroot or cornstarch

Gently stir berries, sugar, and arrowroot together until berries are coated. Set aside.

Crumb Base and Topping

2 cups flour (oat, whole wheat or white)
2/3 cup sugar (coconut or white)
1 teaspoon baking powder
1/4 teaspoon salt
1 1/3 (5.3 oz.) sticks salted butter or margarine
1 egg

For crumb layers, whisk dry ingredients together in another bowl until evenly combined. Add butter and egg; cut in with fork, pastry cutter or smoosh with your hands until blended and crumbly. 
Press about 2/3 of the crumbly dough into the prepared pan then spread berries evenly over top. Clump the remaining dough together and crumble over the berry layer. Bake for 35-45 minutes or until the berries are bubbly and the crumb topping is golden brown. Remove from the oven and let cool before cutting into squares.

Store in an air-tight container or freeze for later!