Sunflower seed flour is a really great addition to your pantry. It is high protein and acts as a good replacement for nut flours if you are allergic. It does have a bit of a heavier taste than almond flour, but is still good for baked goods.
To make: Use raw, hulled sunflower seeds, NOT roasted, as the flavor will be too strong. Using a coffee grinder, place seeds to maximum line and grind for about 30 seconds. Check consistency and see if it is fine enough. If not, grind for another few seconds. Do not grind more than 60 seconds, as sunflower seeds eventually turn into sunflower seed butter.
Storage: Sunflower seeds, like nuts, go rancid quickly. It is best to store the seeds, themselves, in the freezer. I store my sunflower seed flour in a labeled freezer bag in the freezer. It can keep for months.