Preheat your oven to 350°F (175°C) to ensure even baking and a golden topping.
In a medium mixing bowl, combine the mixed summer berries, 2 tablespoons granulated sugar, and 1 tablespoon all-purpose flour. Gently toss until coated. Stir in vanilla extract. Set aside.
In another bowl, whisk together 1/2 cup all-purpose flour, 1/4 cup granulated sugar, baking powder, salt, and ground cinnamon. Pour in melted butter and milk, mixing until just combined with some lumps.
Pour the berry mixture evenly into a small (about 8-inch) baking dish. Spoon the topping over the berries, covering as much as possible.
Bake in the preheated oven for 25-30 minutes until the topping is golden and berry juices bubble around the edges.
Remove from oven and let cool for a few minutes. Serve warm, optionally with vanilla ice cream or whipped cream. Enjoy!