Preheat the oven to 350ºF. This is an essential step, as a properly preheated oven ensures even baking, helping the topping become golden brown while the strawberries bubble nicely.
Make the filling: In a large bowl, combine the strawberries, maple syrup (or honey), arrowroot flour, lemon juice, and vanilla extract. Gently stir until all the berries are evenly coated. This mixture should feel syrupy and fragrant as the ingredients meld together.
Assemble: Pour the fruit mixture, along with any juices, into a 9×9-inch or similarly sized baking dish. Spread it evenly to ensure every bite has delicious strawberries.
Make the topping: In another bowl, mix together the oat flour, rolled oats, coconut sugar, ground cinnamon, and sea salt. Pour in the melted butter, followed by the maple syrup, vanilla extract, and lemon zest. Stir until the mixture forms a crumbly topping that looks inviting and smells heavenly.
Sprinkle the topping evenly over the fruit mixture. Make sure to cover all the strawberries; this will help create a crispy layer!
Bake: Place your baking dish in the preheated oven. Bake for about 55 minutes, or until the fruit is bubbling and the topping is golden brown. If you notice the topping browning too quickly, tent the dish with foil for the last 10 to 15 minutes to prevent burning.
Cool slightly before serving. This is important as it allows the juices to thicken up a bit, making for a perfect serving consistency. Enjoy the crisp as is, or top it with coconut whipped cream or your favorite ice cream for an extra treat!