Preheat oven to 325°F (165°C).
In a large mixing bowl, cream together softened butter, brown sugar, and granulated sugar until light and fluffy.
Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
In a separate bowl, whisk together flour, baking soda, baking powder, and salt.
Gradually add dry ingredients to the butter mixture, mixing until just combined.
Fold in oats, M&Ms (or Reese's Pieces), chopped pecans, butterscotch chips, and Rice Krispies cereal until evenly distributed.
Using an ice cream scoop or spoon, drop cookie dough balls onto ungreased baking sheets, spacing them about 2 inches apart.
Bake for 20-25 minutes, or until edges are golden and centers are set.
Allow cookies to cool on baking sheet for 5 minutes before transferring to wire racks to cool completely.