If your blackberries are frozen let them thaw. Lay blackberries in a larg bowl or pan. Sprinkle sugar evenly across them. Every 5 minutes rotate blackberries until they make a syrup around them. Fold in apple sauce, be gentle or the blackberries will fall apart.
Preheat oven to 350. Place stick of butter in the bottom of a 9x13 in pan then place in the oven to melt the butter in the bottom of the pan.
In a medium mixing bowl, add bisquick, 2 cups of sugar and orange peel zest. Slowly add milk while beating with a whisk. Add more or less milk if needed, batter should be the consistancy of pancake batter.
Pour half of your batter into the bottom of the pan. Lay blackberries over batter spreading evenly. Pour the rest of your batter over the blackberries covering evenly.
Bake for 1 hour or until golden brown on top and edges. Serve with french vanilla ice cream.