Preheat oven to 350 ℉In a large mixing bowl, add the oats, flour, coconut sugar, and cubed butter.
Use a fork or pastry cutter to cut the butter into the mixture until it's combined. It should look like a coarse crumble.
In a 9 x 9 inch square cake pan or baking dish, lined with parchment paper or greased, add ⅔ of the crumble mixture and press down firmly.
Bake the crust at 350 ℉ for 12-15 minutes until golden brown. Remove from oven and set aside. While the crust bakes, make the filling.
Make the filling
In a small saucepan over medium high heat, add the strawberries and maple syrup.
Bring the strawberries and syrup to a boil and then let them cook for 7-10 minutes until they are soft and falling apart.
In a small bowl, whisk together the arrowroot powder and water to make a slurry.In a small bowl, whisk together the arrowroot powder and water to make a slurry.
Turn the heat off and stir in the vanilla extract.
Pour the filling over the crust and spread it evenly, stopping just shy of the edges. Sprinkle the remaining crumble topping over the top
Bake the strawberry crumble bars for 25-30 minutes at 350 ℉ until the filling is bubbly and the top and edges are golden brown.Let the crumble cool completely and then cut it into bars. Store covered in the fridge!