Combine honey, peanut butter, cocoa powder and vanilla in a small sauce pot over medium heat and whisk until ingredients are smooth and fully melted; remove from heat.

Add brown rice cereal to a large bowl. Pour warm chocolate peanut butter mixture over the crispy rice and stir until cereal is evenly coated.

Spread mixture evenly into an 8 x 8 pan and refrigerate for 3 hours before slicing into squares.