Put sunflower seeds into a half gallon mason jar or other container. Add 1 tablespoon of sea salt. Fill with water to the top of the jar. Swirl the water around to dissolve the salt.
Let the seeds sit in the jar in a warm place in your home overnight, or for about 8 hours.
Drain and rinse the seeds and spread them in a single layer on a dehydrator tray.
Dehydrate at 100 to 115 degrees F until crispy. Check by taste to make sure they are crunchy and free of moisture. This usually takes about 24 hours, depending on dehydrator and other conditions, etc. (Drying your seeds below 115 degrees keeps all the enzymes and fragile vitamins intact.)
Part 2: Grinding
Put crispy, dehydrated seeds into your food processor and process into a finely ground meal.
Keep processing until the meal starts to release its oil and come together into a ball. This can take at least 10 minutes. You will probably need to scrape down the sides of the processor a few times to help it along. You might even need to stop the processor and let it cool down a few times.
Continue processing so the ball comes together and falls apart several times as the oils are released by the heat and friction of the processor. Add a little oil to help this process go faster, if needed.
Once the butter is smooth and creamy, mix in salt, sweetener and cinnamon or vanilla, to taste.