In a food processor (or maybe in a blender, if you have a good one), process the sunflower seeds until they are broken up a bit. (I prefer larger pieces, but you can process until a coarse flour if you prefer!).
Add the tahini, coconut butter, and optional sweetener and process just until combined.
Divide among 8 silicone muffin tins and top with mini chocolate chips and sesame seeds. Optional: you can pour into a small parchment-lined glass dish and then cut into 8 squares.
Freeze for at least one hour and then serve. Store in freezer.
Notes
Additional add-ins: add cacao nibs or chunks of coconut butter for some texture and flavor contrast!