Preheat your oven to 375°F (190°C). Prepare the baking dish by lightly greasing it or lining with parchment paper.
Slice ripe peaches into thin wedges, discarding pits, and place them in a mixing bowl.
Add sugar and ground ginger to the peaches, then gently toss everything together until the slices are evenly coated and fragrant.
Transfer the coated peaches into the prepared baking dish, spreading them out into an even layer.
In a separate mixing bowl, combine oats, flour, and brown sugar, stirring to blend.
Add the cold, cubed butter to the dry mixture and use your fingers or a pastry cutter to work it in until the mixture resembles coarse crumbs.
Spoon the crumble mixture evenly over the peaches, covering all the fruit with a crumbly layer.
Place the baking dish in the oven and bake for about 40 minutes, or until the topping is golden brown and bubbling around the edges.
Remove from oven and let cool for a few minutes; the juices will thicken slightly as it rests.
Serve warm, perhaps with a scoop of vanilla ice cream or a dollop of whipped cream for added indulgence.
