Line an 8x8 or 9x9 inch pan with aluminium foil and lightly grease. Or line with parchment paper.
In a medium sauce pan over medium-low heat melt together the butter, brown sugar, honey and corn syrup. Then allow the mixture to come to a low boil for about 2-4 minutes and thicken slightly.
Remove from the heat. Then stir in the vanilla, followed by the quick oats and cereal.
Press the mixture into the prepared pan and press it down tightly. Then sprinkle the M&Ms over top and press them in.
Allow to harden for about 2-3 hours. Then cut into bars.
Notes
Store in an airtight container at room temperature. If placed in the fridge, they get too hard and crunchy.