Preheat oven to 375°F and line an 8x8 metal baking pan with parchment paper.

In a medium bowl, whisk together oat flour, sorghum flour, oats, coconut sugar, baking powder, salt, and cinnamon.

Pour melted butter, maple syrup, and vanilla over the top and mix it together with a rubber spatula until evenly moistened and the shaggy dough sticks together when pinched. Dump ⅔ of the crumble into the prepared baking pan and press down flat and even. Reserve remaining crumble for topping

Bake crust for 13-15 minutes until it begins to turn golden brown.

Meanwhile, prepare the chia jam. Combine the berries and maple syrup in a small saucepan over medium-high heat. Cook, stirring occasionally, until it begins to bubble. Reduce heat to medium low, and cook, breaking up the berries on the side of the pan with your wooden spoon as you stir. Cook for an additional 10-12 minutes until it's thickened quite a bit.

Add chia seeds and lemon juice and cook for 1 more minute. Remove from heat and let cool slightly.

When the crust base is ready, remove it from the oven and let it cool for 10 minutes while you finish the jam.

Pour the warm jam over the par-baked crust and spread it into an even layer.

Sprinkle remaining crumble in an even layer over the top of the jam, crumbling it into small pieces as you go.

Bake for an additional 20 minutes, until topping turns golden brown.

Let cool in the pan for at least 30 minutes before using the parchment paper to slice and serve (speed up this cooling by popping it in the fridge on a wire rack!). Store in an airtight container in the fridge for up to a week and serve cold, room temperature, or warm them in the microwave.