Preheat the oven to 400°F and grease your baking dish.
Place the berries and peaches in a greased 9x13 pan or a 10-12 inch (oven safe) skillet (cast iron works really well here). In a small bowl, mix together the maple syrup, lemon juice, zest, and vanilla. Add the tapioca starch and mix until dissolved. Pour over the fruit and gently mix to coat.
To a medium size bowl, add all the dry topping ingredients and stir to combine. Now, add the coconut oil and oat milk to the dry ingredients. Mix together until a dough forms (it'll be a slightly sticky). Scoop out medium size balls and flatten with your hands before adding on top of the fruit mixture. Repeat until you've used up all the dough.
Place in the oven uncovered and bake for about 30 minutes or until the topping has turned golden brown.
Let cool a few minutes before topping with vanilla ice cream and enjoy!
Makes 8-10 servings.