Line a baking sheet with aluminum foil, wax paper or parchment paper.
In a bowl, mix together the oats and Rice Krispie cereal.
In a microwave safe bowl, mix together peanut butter and honey. Microwave for 30 second intervals until melted. Stir together until mixed.
Stir in the vanilla to the peanut butter mix.
Pour the peanut butter and honey mixture into the oat and Rice Krispie mixture. Fold over until well incorporated.
Add the M&Ms and mix.
Once mixed, press your granola mixture into the foil lined pan.
Top with any extra toppings, pressing them into the granola.
Place in the refrigerator for 3-4 hours or until fully set. Slice into bar shapes and enjoy!