Preheat the oven to 350 F. Combine the ground flax and water in a small bowl, stir, and set aside.
Put the frozen strawberries in a medium pot and turn on the heat to medium. Stir the mixture frequently and after about 5 minutes start to mash the strawberries with a potato masher or wooden mallet. Once mashed, remove from heat and add the chia seeds, orange zest, and 3 tablespoons maple syrup. Stir well and set aside.
In a large bowl combine the oats, both types of flour, and salt. Then add the remaining maple syrup and the coconut oil. Lay the mixture out on a cutting board and form it into a log. Cut it in half and reserve one half for the topping. Put half back into the bowl and add the flax mixture. Combine well, then spread the mixture into an 8-inch x 8-inch baking dish that has been lined with parchment. Bake the crust for 10 minutes.
Now spread the strawberry chia mixture over the top into a thick layer. Top with the reserved oat topping. Bake for 20 more minutes or until the oats are golden brown. Let cool for one hour, slice, and serve.