Preheat oven to 350℉. Line pan with parchment paper, cutting to fit with two opposite sides overlap making it easier to remove from the pan.
In a large bowl, combine flour, oats, brown sugar and salt. Mix in melted butter to create a crumbled texture.
In a large bowl, add the diced strawberries, lemon juice, maple syrup, starch and cinnamon. Gently mix together until the strawberries are well coated.
Press 2/3's of the oat-flour mixture evenly into the square pan. Pour and layer the strawberry mixture and lastly crumble the remaining oat-flour mixture evenly over the strawberry mixture.
Bake for 35-40 minutes in the preheated oven. Allow to cool completely at room temperature. Cut into 9 equal squares and enjoy!
