Preheat and prep: Heat your oven to 350°F (175°C).
Grease an 8x8-inch baking dish or similar with butter or coconut oil.
Make the peach filling: In a bowl, combine peaches, sweetener, vanilla, cinnamon, nutmeg, lemon juice, xanthan gum, and a pinch of salt. Toss until the peaches look glossy and the thickener is evenly distributed. Let sit for 5 minutes to help it thicken slightly.
Spread the fruit: Add the peach mixture to the greased baking dish and spread into an even layer.
Mix the dry topping ingredients: In a separate bowl, whisk almond flour, coconut flour, sweetener, baking powder, salt, and cinnamon.
Add the wet ingredients: Stir in melted butter, egg, vanilla, and 2 tablespoons of heavy cream.
The batter should be thick but scoopable. If it’s too stiff, add another tablespoon of cream.
Top the peaches: Drop spoonfuls of batter over the peaches. It doesn’t need to cover completely—the gaps let steam escape and create that classic cobbler look.
Bake: Bake for 28–35 minutes, until the topping is golden and set, and the fruit is bubbling around the edges.
If the top browns too quickly, tent loosely with foil for the last 5–10 minutes.
Rest and serve: Let the cobbler rest for 10–15 minutes to thicken. Serve warm with a dollop of whipped cream or a scoop of keto vanilla ice cream.