Pre-heat your oven to 180c/350f.
Next you'll need to line your baking tin with parchment/baking paper.
Mix the oats, oat flour, sunflower seeds, coconut oil, maple syrup and vanilla in a large mixing bowl until well combined
2 cups Oat Flour, 1 cup Rolled Oats, ⅓ cup Maple Syrup, ⅓ cup Sunflower Seeds, ⅓ cup Coconut Oil, 1 teaspoon Vanilla Extract
Then transfer ⅔ of the crumble mixture in to your baking tin.
Using the back if a spoon or your fingers, firmly even out the oats to cover the base of the baking tin. Being sure not to leave any gaps.
Spoon the blueberry jam over the base, and spread out until you have a thick even layer.
Then top the jam with the remaining ⅓ of the crumble mixture.
Bake in the pre-heated oven for 35 minutes, until the crumble is golden brown.