Line an 8"x8" pan with a piece of parchment paper.

In a medium pot over medium heat, mix together the nut butter, maple syrup, vanilla and salt.

Stir frequently until it starts bubbling all over. It doesn't need to be big bubbles. Once you see the bubbles starting to form at the edges of the pan, continue to the next step.

If using peanut butter - remove from the heat right away.

If using sunflower seed butter - continue stirring and let bubble for 30 seconds. Watch the clock!

Remove from the heat and stir in the oat flour, oats, cereal and nuts / seeds, if using, until well combined. Taste and add more salt, if needed. Don't be alarmed if the crisp rice cereal seems stale or if the mixture seems hard to chew. Once it's cooled, it'll all be good.

Pat onto the bottom of the prepared pan and press very firmly down to compact them. Once they've cooled almost completely, sprinkle the chocolate chips on top.

Once they've cooled and firmed up, cut into bars. Note that they need a few hours to settle. They're quite hard to chew right after making them.

Store in an airtight container at room temperature for 4-5 days. I haven't tried freezing them.