1. Preheat the oven to 400°F. Grease a 9” pie dish and place on a baking sheet lined with a silicone mat or parchment paper.
2. In a medium bowl, gently mix together blackberries, ½ cup of cane sugar, lemon juice, vanilla extract, and cinnamon. Mix in cornstarch until all of the berries are well coated. Spoon into the prepared pie dish and dot with butter.
3. In another bowl, whisk together flour, baking powder, sugar, salt, and cream of tartar.
4. Cut in butter with a pastry cutter or fork until mixture resembles coarse crumbs.
5. Make a small well in the center of the mixture, and pour in milk and buttermilk. Toss with a fork until mixture is evenly moistened. Dough will be very sticky and shaggy.
6. Turn out dough onto a floured work surface. Sprinkle with more flour. Gently knead dough 5 or 6 times until it is workable. Dust with more flour if needed. Don’t overwork your dough, or your biscuits will be tough.
7. Gently pat dough to a half inch thick. Cut out biscuits with a small 1 ½-inch biscuit cutter, dipping it in flour to prevent sticking. Re-roll dough if more biscuits are needed.
8. Place biscuits on top of berry mixture, nestling them close together, leaving only small gaps for steam to escape. Brush with a little milk.
9. Bake the cobbler for 10 minutes. Reduce heat to 350°F, bake an additional 55 minutes, until biscuits are golden brown and filling is bubbly.
More than half the blackberries grown in Oregon are of the Marion variety, they are known as Marionberries. The result of cross breeding between the Chehalem and Olallie blackberries, the Marion blackberry was released in 1956 after extensive testing in it’s namesake Marion County, Oregon. The medium-sized berries are conical in shape, longer than they are wide, and appear dark purple to black in color. The fruit has a tart, earthy sweetness, perfect for eating fresh from local farms and markets. As of July 2017, Marionberry Pie has been designated the official state pie of Oregon.