Line an 8" x 8" square pan with parchment paper, leaving an overhang on all sides.
Place the tahini and honey in a large heatproof bowl and heat in the microwave or over a pan of simmering water until the tahini and honey are melted. Stir to combine.
Add the cereal to the bowl and stir to coat well. Pour into your prepared pan and use slightly damp hands to press firmly and evenly. Sprinkle with the salt (if using) and place in the fridge or freezer to set.
Use the parchment to transfer to a cutting board and cut into 16 squares. Store in an airtight container in the fridge or freezer.
Notes
Swap the tahini for any nut or seed butter.
Swap the honey for maple syrup or another liquid sweetener.
I use an 8 x 8 pan but any size or shape will work!
When using tahini I suggest keeping these bars in the freezer for the firmest texture. Almond or peanut butter bars can be stored in the fridge.