Coat an 8-inch square baking pan with cooking spray. Line the pan with parchment paper, leaving an overhang on opposite sides to lift the bars out easily afterward. Coat the parchment with cooking spray.
Add the brown sugar, honey, and butter to a small saucepan and set over medium-high heat. Cook, stirring frequently, until the sugar has dissolved. Bring the mixture to a simmer then reduce the heat to low and continue to cook for 1 more minute. Turn off the heat and stir in the vanilla extract.
Mix the oats and rice cereal together in a bowl until well combined. Pour the melted butter mixture over the oats & rice then stir with a rubber spatula until well combined. All of the dry ingredients should be moistened. Pour the mixture into the prepared baking pan. Spread in an even layer and press hard to make sure the mixture is compact so the bars don't turn out crumbly. Sprinkle the chocolate chips over the top of the mixture and lightly press down on them with the spatula so they stick to the granola mixture.
Allow to set for at least 2 hours or place into the refrigerator for at least 30 minutes to speed things up. Use the parchment handles to lift out then cut into bars. Individually wrap the granola bars with plastic wrap and store at room temperature for up to 5 days.