1) Preheat the oven to 180C/Gas 4. Line cookie sheets with baking paper or nonstick baking mats.
2) In a very large mixing bowl, combine the eggs and sugars. Mix well. Add the salt, vanilla, peanut butter, and butter. Mix well. Stir in the smarties, chocolate chips, sultanas, if using, bicarbonate of soda, and oatmeal. Drop by tablespoons 5cm apart onto the prepared cookie sheets.
3) Bake for 8 to 10 mins. Do not overbake. Let stand for about 3 mins before transferring to wire racks to cool. Once cool, store in large resealable plastic bags.