Preheat the oven to 400 degrees F. Grease an 8x8-inch or a smaller casserole baking dish with butter or oil.
In a large bowl, toss the berries with flour, sugar and zest. Transfer the berries to the baking dish and set aside.
In a medium bowl, whisk together the flour, sugar, baking powder, baking soda and cinnamon. Cut in the butter using a pastry cutter until small pea-sized pieces are formed.
In a small bowl or measuring cup, whisk together the buttermilk, oil and vanilla. Add the buttermilk-oil mixture to the dry ingredients and mix until just moistened. Do not over mix. Drop the batter onto the fruit forming 6 even mounds. Sprinkle the tops with more sugar.
Bake for 25-30 minutes, until fruit is bubbly and top is golden. Let stand for at least 10 minutes before serving and enjoy!