1. Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper or lightly grease them.
2. Cream the butter and sugar: In a large mixing bowl, beat together the softened butter and packed brown sugar until light and fluffy.
3. Add the eggs and vanilla: Add the eggs one at a time, mixing well after each addition. Then, stir in the vanilla extract.
4. Mix dry ingredients: In a separate bowl, whisk together the all-purpose flour, baking soda, salt, and baking powder.
5. Combine wet and dry ingredients: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
6. Add the oats and mix-ins: Stir in the rolled oats, chocolate chips, shredded coconut, chopped nuts, and raisins (if using). Make sure everything is evenly distributed.
7. Shape the cookies: Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
8. Bake the cookies: Bake in the preheated oven for 10-12 minutes or until the edges are golden brown, and the centers are set.
9. Cool the cookies: Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.
