Crumbly Blackberry Cobbler

Ingredients (13)

• + 3 tablespoons cornstarch add to pantry
• ✓ ¼ cup cold water
• + 4 cups fresh blackberries add to pantry
• ✓ ½ cup white sugar
• + ½ cup brown sugar add to pantry
• + 1 teaspoon vanilla extract add to pantry
• + 1 cup cornflakes cereal, coarsely crushed add to pantry
• + 1 cup all-purpose flour add to pantry
• + ½ cup old-fashioned rolled oats add to pantry
• + ½ teaspoon pumpkin pie spice add to pantry
• ✓ ½ teaspoon salt
• + ¼ cup butter add to pantry
• + ¼ cup melted butter add to pantry