Line a standard loaf pan with parchment and set aside. Put sunflower seeds into a food processor or blender and blend until it's a very fine-like flour.
Combine sugar, water, and oil in a medium saucepan over medium low heat and bring to a boil. Boil for about 40 seconds then remove from heat and add floured seeds and salt. Stir ingredients together very well and scrape into prepared pan then flatten down with spatula. Lay a second piece of parchment over top and press down firmly for a minute or two until very tightly packed.
Allow to cool completely at room temperature or in refrigerator before serving.