Lightly coat an 8-inch square baking pan with nonstick cooking spray, then line with parchment paper; set aside.
In a large bowl, stir the oats and rice cereal together; set aside.
In a small saucepan, bring the brown sugar, honey, and butter to a boil over medium-high heat, then lower the heat to medium-low and simmer until the sugar dissolves, about 2 minutes. Remove from heat and stir in the vanilla extract.
Pour the melted mixture over the dry ingredients and mix well until everything is moistened.
Pour the oat mixture into the prepared pan and press down firmly to ensure the ingredients are tightly compacted. Sprinkle the top evenly with the mini chocolate chips and press down lightly with the back of a spoon.
Cool at room temperature for a couple of hours, then slice into bars.