- With the rack in the middle position, preheat the oven to 425°F (220°C). Line a baking sheet with a silicone mat or parchment paper.
- In a food processor, combine the flour, icing sugar, baking powder and salt. Add the butter and pulse until the butter forms pea-sized pieces. Add the yogurt and ice water. Pulse until the dough just comes together. Add more water, if needed. Form the dough into a disc.
- On a lightly floured surface, roll out the dough until it measures 14 inches (35 cm) across. Transfer to the baking sheet.
- In a large bowl, mix the fruit with the sugar and the cornstarch. Place the fruit in the centre of the dough, leaving a 2-inch (5 cm) border. Fold the edges of the dough toward the fruit. Brush the dough with milk and sprinkle with sugar to taste.
- Bake for 30 minutes or until the crust is golden. Serve with yogurt for breakfast or with ice cream for dessert.