Preheat your oven to 350 degrees F.
To start, make the filling. Add the strawberries, maple syrup, and orange juice into a saucepan. Heat until the mixture starts bubbling, then reduce heat to low and simmer for 7-10 minutes, STIRRING FREQUENTLY, until mixture is thickened. Set aside and let cool.
Then, make the crust. Add the dry crust ingredients to a bowl and whisk together. Then, add the rest of the crust ingredients and mix until incorporated. There should be no loose flour, but mixture will be crumbly.
Line a 8x8" square pan with parchment paper. Add in the crust mixture ONLY, pressing down with your hands until a flat layer is formed.
Bake the crust for 10 minutes at 350 degrees F.
While the crust is baking, make the crumble by adding the crumble ingredients to a mixing bowl. Mix the ingredients until it starts to clump up. Then, use your hands to keep mixing until there is no more loose flour in the bowl.
After 10 minutes, take the crust out and add the strawberry filling on top. Spread the filling out with a spatula until it's in an even layer. On top of that, add the crumble in as even of a layer as possible.
Put the pan back in the oven for 20-25 minutes.
When done cooking, LET THE CRUMBLE COOL for at least 15 minutes before cutting. If you try to cut the bars too soon, they'll likely fall apart.
Once the crumble has cooled down, cut into bars of any size you'd like.
These are especially delicious when served with vanilla ice cream. Enjoy!