Preheat oven to 350 degrees. Brush melted coconut oil in 8- inch baking dish to prevent sticking.
Place the peeled and sliced peaches, lemon juice and vanilla extract in a large saute pan over medium-low heat. Heat until peaches are warmed through and juicing. About 5 minutes.
Turn off burner and stir in arrowroot powder. Be sure to mix thoroughly.
Pour peaches into greased baking dish.
For the crumble, combine all ingredients in a small bowl. Stir until well combined. Evenly spread the topping over the peaches.
Bake the peach crumble for 30 to 35 minutes or until the top is golden brown.