In a mixing bowl, combine the strawberries, blueberries, and raspberries. Add ½ cup of granulated sugar, cornstarch, lemon juice, and vanilla extract. Toss gently until the berries are well coated. Set aside to marinate for 15 minutes.
In another bowl, whisk together the flour, remaining ½ cup of sugar, baking powder, and salt.
Pour in the melted butter and milk into the dry ingredients. Stir until just combined; do not overmix.
In a lightly greased 9x9 inch baking dish, pour the berry mixture evenly on the bottom.
Dollop the cobbler batter over the berries, spreading it out gently. It’s okay if some berries peek through.
Sprinkle the top of the cobbler with cinnamon for added flavor.
Bake in the preheated oven for about 35-40 minutes or until the top is golden brown and the berries are bubbling.
Once done, remove from the oven and let it cool for at least 10 minutes before serving.
Notes
Serve warm with a scoop of vanilla ice cream on top and a sprinkle of fresh berries for garnish.