1/3 cup brown sugar. Ingredients. Topping: Mix dry ingredients for the topping, then add the melted margarine. Mulberry crumble pie. Place into a greased (Pam) 8x8 baking dish. Makes one 23cm open tart. 1/3 cup mulberry syrup or maple syrup -1 single 9-inch pie crust-3-4 c mulberries-1 c sugar-1/4 c flour-Juice of one lemon Crumble Topping:-1/2 c flour-1/2 c oats-1/4 c butter-1 tsp cinnamon-> Preheat oven to 400 degrees. 1kg mulberries, stems removed. Pour into prepared pie shell. 2 cups rolled oats. 1 cup plain flour. I packed the berries in as much as I could. Filling: Gently mix fruit in a large bowl with flour and sugar. 1 egg white. 1 tsp cinnamon. 1 tsp baking powder. The first mulberry harvest of the year. Oat crust. Filling. Combine berries, flour, sugar and lemon juice. Preheat oven to 375. 120g cold butter, cut into small cubes.