Preheat your oven to 375°F (190°C). Grease a baking dish with oil to prevent sticking.
In a large mixing bowl, combine the sliced peaches with lemon juice, vanilla extract, and a pinch of ground ginger. Toss until the peaches are evenly coated and set aside to macerate slightly.
In a separate bowl, whisk together the flour, sugar, cinnamon, and salt. Add the cold butter pieces and use a pastry cutter or fork to cut the butter into the mixture until it resembles coarse crumbs.
Add the oats, brown sugar, vanilla, and ground ginger to the streusel mixture. Toss gently to combine, ensuring the oats are evenly distributed.
Spread the peach mixture evenly in the prepared baking dish, creating a generous layer of juicy fruit.
Sprinkle the streusel mixture evenly over the peaches, covering the surface completely for a uniform golden crust when baked.
Place the baking dish into the oven and bake for about 40 minutes, or until the topping is golden brown and the fruit is bubbling around the edges.
Remove the peach crisp from the oven and let it cool for a few minutes. This helps the juices settle and the topping to firm up slightly.
Scoop the warm peach crisp into bowls, revealing the juicy fruit beneath the crispy topping and enjoy while still warm.