Pre-heat the oven at 350°F and grease 9*9 baking dish.
In a large bowl, add sliced peaches, lemon juice, vanilla extract, cornstarch, granulated sugar, and salt, toss everything to coat evenly.
Pour the peach mixture into greased baking dish and set it aside.
In a mixing bowl, add rolled oats, flour, brown sugar, granulated sugar, ground cinnamon, grated nutmeg, salt, chopped pecan nuts and cold diced butter. Now using your fingers work on the mixture until crumbly.
Sprinkle the topping evenly over peach filling in baking dish.
Bake for 35-40 minutes or until the topping is golden brown, set and fruit is bubbling.
Remove from the oven and allow the dessert to cool for 8-10 minutes. Dish out and serve warm with vanilla ice-cream or sweetened cream.