Make the nectarine filling:
Preheat the oven to 375°F with a rack in the center position
Lightly grease a 10-inch oven-safe skillet with butter
To the skillet, add nectarines, sugar, lemon juice, cornstarch, vanilla, and a pinch of kosher salt
Still to combine. Set aside while you make the toping
Make the crisp topping:
In a medium bowl, combine the oats, flour, pecans, brown sugar, cinnamon, and salt
Pour melted butter over the top, and stire
Sprinkle topping over the fruit in an even layer
Pro tip: you can truly sub out so many fruits if you don't have, or like, nectarines! Use plums, cherries, peaches, or a handful of raspberries or strawberries!