Line an 8-inch square cake pan with parchment paper and set aside.
Add the honey and peanut butter to a large pot over low heat and stir until combined.
Use a spatula to fold in the Cheerios and peanuts, being careful not to crush the Cheerios, until the Cheerios and peanuts are completely coated.
Transfer to lined cake pan and use your spatula to lightly press the mixture down flat.
Refrigerate until completely solid—about 3 hours. Cut into bars in the size of your choice. Sprinkle on some sea salt for a salty-sweet finish (optional).
Individually wrap and store in the refrigerator.