Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
In a bowl, whisk together flour, baking soda, baking powder, and salt. Set aside.
In a stand mixer, beat butter, granulated sugar, and brown sugar until light and fluffy (~3 minutes).
Add eggs one at a time, then mix in vanilla.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Fold in oats, chocolate chips, coconut, and pecans with a spatula.
Drop ¼-cup portions of dough onto baking sheets (space 3" apart). Flatten slightly.
Bake for 12–15 minutes until edges are golden but centers are soft.
Let cookies cool on the sheet for 5 minutes, then transfer to a wire rack.
