In a large bowl, stir oats and rice cereal together. Set aside.
In a small pot set to medium heat, melt butter, honey and brown sugar together until bubbly. Reduce heat to low and cook for 2 minutes. Stir in vanilla. Pour over dry ingredients and mix well to moisten all ingredients. Pour mixture onto a lightly greased baking sheet (about 12 x 8 inches). Press mixture to 3/4-inch thickness. (If your pan isn't small enough, pack mixture into one side. You really want to press them down so they stick together. A greased rubber spatula helps with this!)
Sprinkle with mini chocolate chips and press down lightly. Refrigerate pan at least 1 hour, or until set, before cutting into bars. Wrap bars in parchment or plastic wrap and store at room temperature, or in your refrigerator, for up to 1 week.