Spray an 8x8 baking dish with a light coating of non stick spray and then line with parchment paper. Set aside
In a large bowl combine oats and cereal
In a small saucepan, combine butter, brown sugar and honey over med-high heat. Stir until butter and brown sugar are melted and all ingredients are well combined.
Bring to a boil. Reduce heat and let simmer for 2 minutes, whisking constantly.
Remove from heat and stir in vanilla.
Add honey mixture to oatmeal mixture and mix well. Make sure ALL the oats are coated, you can't have any dry spots or it will crumble!
Once mixed, put into 8x8 dish and press down with the back of a spoon or your hands. Press and press and press. Make sure it is as pressed and compacted as you can make it! When you think you pressed enough, press more!
Cover and refrigerate for at least an hour. Remove from fridge and remove from dish using the parchment paper as handles. Place on cutting board and cut in half and then cut each half in 6 pieces.
Store in refrigerator.