Line an 9x9 baking pan with parchment paper.
In a small saucepan, combine maple syrup, peanut butter, and 1/4 teaspoon sea salt over low heat stirring occasionally until mixture is completely incorporated and smooth.
In a medium bowl, place brown rice cereal and pour peanut butter mixture on top. Stir mixture until the rice cereal is completely coated. Transfer rice cereal mixture to prepared baking pan and using an extra sheet of parchment paper, press mixture into pan. Be sure to pack the mixture down firmly into an even layer. Place pan in freezer for 30 minutes to an hour until layer has hardened. Remove from freezer, use parchment to lift hardened layer out of baking pan and place atop a cutting board (layer will be thin). Cut into squares about an inch or slightly larger.
Place chocolate into a microwavable safe bowl and melt chocolate in microwave for 30 second intervals, stirring after each interval until mostly melted.Stir until lumps are smooth. Allow chocolate to cool for a few minutes before coating squares.
Chocolate coating: Cover a cookie sheet with a piece of parchment paper. Place square in bowl of chocolate, flip with fork to coat, allow extra chocolate to drip off from fork, and place onto prepared piece of parchment paper. Wiping the bottom of the fork against the side of the bowl is helpful. Sprinkle with sea salt. Repeat until all squares are coated. Place cookie sheet in refrigerator until chocolate has hardened. Your hands will inevitably get sticky and chocolatey - it helps to have a wet paper towel nearby.
Store in an airtight container.