Line an 8x8-inch baking pan with parchment paper or foil, and set aside.
In a large bowl, stir together the oats, Coco Pops, and cinnamon.
In a large microwaveable bowl, add the peanut butter and honey, and heat in 20 - 30 second intervals until the peanut butter is runny and can be combined easily with the honey. Stir in the vanilla.
Fold in the oats mixture until evenly coated. Use your hands if you need to. Fold in the chocolate chips, and 1/2 cup (100g) of M&Ms.
Press the mixture firmly into the prepared pan (using your hands if needed), then press the remaining M&Ms on top. Cover, and refrigerate for at least 3 - 4 hours before removing and cutting into bars.
Video
Notes
Leftovers can be stored in an airtight container in the fridge for up to 2 weeks. They also freeze well for up to 3 months. Thaw overnight in the fridge before eating.