01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, baking soda, and salt in a medium bowl.
03 - Beat softened butter, brown sugar, and granulated sugar until light and fluffy, about 2 minutes.
04 - Beat in eggs one at a time, then stir in vanilla extract.
05 - Gradually mix in dry ingredients until just combined.
06 - Gently fold in candy-coated chocolates, pretzel pieces, rice cereal, white chocolate chips, marshmallows, sprinkles, and nuts if using.
07 - Drop heaping tablespoons of dough onto prepared baking sheets, spacing 2 inches apart.
08 - Bake for 9-11 minutes until edges are lightly golden. Centers will appear slightly underbaked.
09 - Let cookies cool on baking sheets for 5 minutes before transferring to a wire rack to cool completely.