Preheat the oven to 400℉.

Start the Peaches

• Heat a 10 or 12-inch cast iron skillet over medium-high heat. Melt the butter then add the peaches, cinnamon, and salt. Cook, stirring, until the peaches thaw and begin to release their juices, about 5 minutes. Add the coconut sugar, maple syrup, vanilla extract, and lemon zest, stir and bring to a simmer. Once simmering, remove from the heat, and sprinkle in the tapioca and stir into the peaches so that there are no clumps and it is smooth. Spread the peaches into a single layer and set aside to allow to cool slightly.

Make the Crumble

• Meanwhile, in a medium bowl, combine the oats, gluten-free flour, coconut sugar, maple syrup, and diced butter. Using your hands or a pastry cutter, mash and stir until the butter is well combined and it resembles a coarse crumbly mixture.

Finish the Peach Crumble

• Sprinkle the crumble over the peaches evenly. Transfer to the oven and bake until the topping is golden and the peaches are bubbling, about 20 minutes.
• Remove from the oven and let cool for 5 to 10 minutes before serving. Spoon and serve alone or finish with a scoop of vanilla ice cream!