For the strawberry filling, place a medium saucepan over low heat. Add the strawberries, maple syrup, cornstarch, cinnamon, and salt to the saucepan and bring to a boil. Simmer for 5 minutes, stirring frequently. Use a wooden spoon to press down and break down the strawberries just a bit. Cook until mixture is thickened up without being too drippy. Set aside to cool.
Preheat oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper making sure to leave an overhang of 1" (2.5 cm). You will use these as handles to pull the bars out later.
In a large bowl, mix together the oat flour, oats, coconut or brown sugar, cinnamon, baking soda, and salt.
Add in coconut oil and vanilla extract. Stir just until the dough begins to clump together. Do not overmix!
Place 2/3 of the mixture into the prepared pan. Place the remaining mixture into the fridge. Use your hands, a cup, or a spoon to evenly press the dough down into the baking pan.
Pour the strawberry filling over the crust. Spread the mixture evenly.
Take the remaining oatmeal topping out of the fridge. Sprinkle the crumbles over the filling. Sprinkle a small handful of oats on top.
Bake for 20-25 minutes or until filling is bubbly and topping is golden.
Allow bars to cool completely. Use a sharp knife to cut into 9 bars. Bars can be served cold from the fridge, room temperature, or warmed up in the microwave.
Add ¼ cup chopped nuts to the crust and crumble mixture for an extra crunch.
Swap out the strawberries for fresh blueberries, blackberries, or raspberries.
Storage tips:Keep them for up to 5 days in the fridge or up to 3 months in the freezer stored in an airtight container or ziploc bag.