PREP: Preheat the oven to 350 degrees F. Lightly grease a 9x13-inch ceramic or glass pan. Do not use metal; it can cause the fruit to have a metallic flavor.
FILLING: Prepare the peaches (SEE NOTE 1). Add chunks of peaches to a large bowl. Toss gently with lemon juice. Add in the dark brown sugar, white sugar, cinnamon, nutmeg, cornstarch, salt, and vanilla. Stir gently until combined and then transfer to the prepared pan along with any accumulated juices. Bake filling (without topping) for 10 minutes.
CRUMBLE TOPPING: Melt the butter and allow plenty of time for it to come back to room temperature. If it is too hot, it will melt the sugar and make the topping greasy. In a large bowl, combine the flour, baking powder, salt, sugar, and vanilla; stir. Add the room temperature melted butter into the mixture and stir until just combined. Do not over-mix. Crumble with your fingers and sprinkle over the partially baked peaches. Do not press the crumble mixture down . Return to the oven for 35 more minutes.
CRUNCHY TOPPING: In a small bowl, stir together the sugar and cinnamon. Sprinkle evenly on top of the crumble topping. Return to the oven for 10 minutes. If desired, broil for 2-3 minutes on HIGH for a super-crisp topping. Remove from the oven and let stand for 20-30 minutes to thicken and gel. Serve with fresh whipped cream or vanilla bean ice cream. (See Note 2.)
Video
Notes
NOTE 1: Peach prep:
Use a paring knife to cut off the skin; halve the peaches, remove the pit, and chop for this dessert.
Briefly boil (blanch) the peaches:
For unripe peaches: Using a paring knife, score a small "X" in the bottom of the peach and then place the peach in boiling water for about 60 seconds. Using a slotted spoon, remove the peach from the boiling water and place it in a large bowl filled with ice and cold water. As soon as the peach is cool enough to handle, use a paring knife to remove the softened skin (it should slide off pretty easily).
For ripe peaches: Place the peach in boiling water for about 30 seconds. Using a slotted spoon, remove the peach from the boiling water and place it in a large bowl filled with ice and cold water. As soon as the peach is cool enough to handle, gently peel off the softened skin with your fingers. (It should slide right off.)
Note 2: Broiling: Broiling the Peach Cobbler at the end of the baking time makes it crispy and crunchy. Use caution, though, depending on the type of pan you use. Some types are not suitable for the broiler.