Preheat your oven to 375 degrees f.
Lightly grease a medium baking dish with a little coconut oil or ghee.
In a large mixing bowl, combine your peach slices, lemon zest, lemon juice and vanilla.
Sprinkle the peach slices with your Arrowroot powder (or flour/cornstarch) and give everything a good toss to combine.
Transfer this peach mixture to a baking dish.
In the same bowl (no need to clean it) combine your almond meal, oats, chopped walnuts, sea salt, and cinnamon.
Add in the honey and melted butter, then thoroughly stir to get a wet crumbly mixture.
Sprinkle this crumble mixture over your peaches in the baking dish.
Bake in the middle rack of your oven, for 30-35 minutes, or until golden and crisp on top and the peaches are soft and bubbly.
Consider topping with a high-quality vanilla yogurt or vanilla bean ice cream.