Preheat the Blackstone griddle to medium heat. Melt 3 tablespoons of butter on the griddle, add the sliced peaches, and toss to coat. Cover with a dome and cook, checking every few minutes, until the peaches soften.
Remove the dome and add the remaining 2 tablespoons of butter. Once melted, sprinkle in the brown sugar, cinnamon, honey, and a pinch of salt if using. Toss gently and cook until the peaches are glossy and bubbling in a caramel-like sauce, about 3–5 minutes.
On another section of the griddle, melt 3 tablespoons of butter. Add the oats, toss to coat, and spread into an even layer. Sprinkle with extra brown sugar and cinnamon if desired. Toast, flipping occasionally, until golden, nutty, and crisp, about 2–3 minutes.
To serve, scoop vanilla ice cream into bowls. Spoon the warm griddled peaches and sauce over the ice cream, then finish with a generous sprinkle of toasted oats. Serve immediately and enjoy.