Preheat oven at 350-degree Fahrenheit and prepare an 8-inch square baking dish by greasing it and then sticking the parchment paper in it. In a nonstick pan combine raspberries, chia seeds and dates. Cook at high flame for 2-3 minutes or until raspberries are mushy. Turn it off and let it cool down a bit.
In a blender combine the cooked raspberries and 2 tbsp. water and blend it as smooth as possible. Spoon it out in a bowl and keep it aside.
In another mixing bowl combine the dry ingredients (oat flour, almond flour, oats, salt) and mix it with a spoon. Keep it aside.
In a blender combine wet ingredients (oat milk, vanilla extract and 1/4 cup dates) and blend it smooth.
Now, fold in wet ingredients into the dry ingredients and make a dough like batter. It should not firmly stick to each other but should be crumbly and soft and ready to stick to each other.
Now, keep about 2 tbsp. of the dough aside in another mixing bowl. Crumble this dough making sure its not sticking to each other. Then, add the other topping ingredients (oats, almonds and brown sugar).Mix it with a spoon and keep it aside.
Now, start the first layer by placing the dough from step 5 at the center of the prepared baking dish. Press it firmly with your fingers and shape it accordingly to the baking dish.
Then, add second layer of the blended raspberry from step 2 covering the entire dough.
Lastly, top it with the toppings from step 6 covering it evenly.
Place it in the middle rack of the oven. Bake it for 30 minutes. Turn it off and let it cool completely. Gently take out the parchment paper along with the bar and place it on the flat surface. Slice it with a sharp knife and enjoy.