Place the peaches cut side up in a basking dish. Place the almonds and sugar in the bowl of a food processor, and pulse until coarsely ground. Add the oats, cinnamon, salt, and butter, and pulse a few times, just until incorporated. Scoop the almond mixture into the center of each peach, then press the topping flat. Bake 45 minutes to 1 hour, until the peaches are easily pierced with a fork, and the topping is crisp and golden brown. Serve warm or at room temperature, plain, or with crème fraîche or whipped cream on top.