Toss the crushed graham crackers in a bowl with the oats and rice cereal.
Heat the honey, light brown sugar, and butter in a small saucepan until boiling. Lower the heat to low and cook until the sugar dissolves, about 3 minutes, then whisk in the vanilla extract.
Pour the honey mixture over the oat mixture and toss to completely coat, let cool slightly.
Add the chocolate chips and marshmallow bits into the oat mixture.
Line a square baking pan with parchment paper.
Press the oat mixture into the prepared pan with a spatula.
Cool completely in the pan and cut into bars.
Wrap the granola bars individually with plastic wrap or enjoy immediately.