Citrus cobbler with berries

Ingredients:

For the test:

• 1/4 cup whole wheat flour
• 1/4 cup premium wheat flour
• 2 tbsp plus 1 tsp sugar, in portions
• 1/2 tsp baking powder
• 1/4 teaspoon baking soda
• 1/4 teaspoon salt
• 2 tbsp chilled butter, cut into small pieces
• 1/3 cup low-fat buttermilk
• 2 tbsp. l. canola oil

For the filling:

• 1/4 cup whole wheat flour
• Cooking spray
• 1/4 cup sugar
• Finely grated zest of 1 orange (about 2 tsp)
• 2 packs (340 g, about 6 cups) frozen mixed berries (defrosted)

Preparation:

1. Preheat oven to 400°F (205°C). Spray an 8x8 inch baking dish with cooking spray.
   
   In a large bowl, combine the berries with whole-wheat flour, sugar, and zest. Transfer the berry mixture to a baking dish.
2. In a medium bowl, combine whole-wheat flour, all-purpose flour, 2 tablespoons sugar, baking powder, baking soda, and salt. Using 2 knives or a pastry cutter, chop the dough until it forms small, pebble-sized pieces.
3. In a small bowl or pitcher, combine the buttermilk and canola oil. Add this mixture to the dry ingredients and mix until moistened. Do not overmix. Spoon the batter over the fruit, forming 6 mounds. Sprinkle with the remaining 1 teaspoon of sugar.
   
   Bake for 30 minutes, until the fruit begins to bubble and the top is golden brown. Let stand for at least 10 minutes before serving.