1. Place the peach wedges in a large bowl and toss with 1/4 cup sugar.

2. Let the peaches rest for about 40 minutes so they release their natural juices.

3. Partway through the resting time, preheat the oven to 410°F.

4. Drain the peaches in a colander and reserve the released juice.

5. Measure 1/4 cup of the peach juice into a large bowl.

6. Add the cornstarch, 1/8 teaspoon salt, and lemon juice to the reserved juice and mix until smooth.

7. Add the peaches back to the syrup and toss gently to coat.

8. Taste the filling and adjust with a little more sugar or lemon juice if needed.

9. Transfer the peaches and syrup to a medium glass or ceramic baking dish.

10. Bake the peaches for 12 minutes.

11. Meanwhile, whisk together the flour, 1/3 cup sugar, baking powder, baking soda, and 1/4 teaspoon salt.

12. Add the butter and rub it into the dry ingredients with your fingertips until the mixture resembles coarse crumbs.

13. Add the yogurt or sour cream and gently fold until a soft dough forms.

14. Remove the peaches from the oven.

15. Crumble pieces of the biscuit dough over the peaches, leaving small gaps between the pieces.

16. Sprinkle the topping with demerara sugar and cinnamon.

17. Bake for about 20 minutes, or until the biscuit topping is golden and cooked through.

18. Let the peach cobbler rest for 20 minutes so the syrup can thicken.

19. Serve warm with vanilla ice cream or whipped cream.