Preheat oven to 350 degrees.
Combine berries, chia seeds, lemon juice, lemon zest and maple syrup in a bowl. Mix well and set aside.
Combine the rest of the ingredients and cut in cold butter using a fork or a food processor until crumbly.
Coat an 8×8 baking dish with cooking spray. Add filling, followed by topping.
Bake for 30 minutes or topping is golden brown.
Let cool for at least 5 minutes before serving