Preheat the oven: Set to 350°F (175°C). Place a 9- or 10-inch oven-safe skillet on the stove.
Prep the strawberries: Add strawberries to the skillet with sweetener, lemon zest, lemon juice, vanilla, cinnamon, and salt.
Stir over medium heat for 3–4 minutes, until the berries start releasing juices.
Thicken the fruit (optional): Sprinkle xanthan gum lightly over the berries while stirring. Cook another 1–2 minutes until slightly thickened. Remove from heat.
Make the topping: In a bowl, mix almond flour, shredded coconut, sweetener, baking powder, and salt.
Add melted butter and vanilla. Stir until the mixture turns crumbly and moist.
Assemble: Scatter the crumble evenly over the strawberry layer. Don’t press it down; loose crumbs crisp better.
Bake: Transfer the skillet to the oven and bake for 18–22 minutes, until the topping is golden and the edges are bubbly.
Rest: Let it cool for 10 minutes.
The filling will thicken as it stands.
Serve: Spoon into bowls and top with whipped cream or keto ice cream if you like. Garnish with mint.