Preheat oven to 350°F. Brush 9" baking pan with oil and line with parchment paper.
In large bowl, whisk together oil, buttermilk, eggs, vanilla, and 1 cup sugar. In separate bowl, whisk 1 1/2 cups flour, baking powder, baking soda and salt together to combine. Whisk wet ingredients into dry until just combined. Toss berries on a plate with remaining Tbsp flour, then fold into batter and transfer to baking dish. Sprinkle to evenly coat remaining 2 Tbsp sugar on top.
Bake until golden, 50-55 minutes until toothpick inserted in center comes out clean. Let cool slightly before serving.