Warm the peaches: In a small saucepan over medium heat, add sliced peaches, 1 tablespoon maple syrup, ½ teaspoon cinnamon, and a pinch of salt.
Cook 3–5 minutes until the peaches soften and release juices. Transfer half to a bowl for topping and keep the rest in the pan.
Add the oats: Pour in 1 ¾ cups milk with the peaches in the pan. Stir in oats, remaining ½ teaspoon cinnamon, nutmeg, and vanilla.
Bring to a gentle simmer.
Simmer to creamy: Cook 5–7 minutes, stirring often, until the oats are tender and creamy. If it gets too thick, splash in the remaining milk.
Boost with protein: Remove from heat. Whisk protein powder with a few tablespoons of warm oat mixture in a cup to form a smooth paste.
Stir this back into the pot. Add chia or flax if using. Sweeten with more maple to taste.
Toast the “crumble”: In a small skillet, melt coconut oil over medium heat.
Add chopped nuts and a tiny pinch of salt. Toast 2–3 minutes until fragrant and slightly golden. Remove from heat.
Assemble: Spoon oatmeal into bowls.
Top with reserved peaches, toasted nuts, and a dollop of Greek yogurt or an extra splash of milk. Serve warm.