1. Preheat oven to 375°F (190 °C).
  2. Toss the peaches, raspberries & blueberries with 3 tbsp (38 g) of sugar and ¼ tsp of the cinnamon and spread on the bottom of an 8 cup (2 L) baking dish.
  3. Whisk the eggs, the remaining ½ cup (100 g) of sugar and melted butter together in a large bowl. Whisk in the milk. Sift in the flour, cornmeal, baking powder and salt and stir until combined (the batter will be wet).
  4. Spoon the batter over the fruit, leaving a little space between spoonfuls to allow for expansion as the cobbler bakes. Stir a little sugar and cinnamon together and sprinkle this overtop the cobbler.
  5. Bake for 35 to 45 minutes, until the peach juices are bubbling and the topping is cooked through (you can lift a piece up to check that it is cooked through).

Serve the cobbler warm with ice cream.
The cobbler will keep when refrigerated for up to 2 days.