Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper.

In a large bowl, cream the softened butter with granulated and brown sugars for 2 to 3 minutes until light and fluffy. Scrape the bowl down once or twice.

Add eggs one at a time, beating well after each addition. Stir in the vanilla.

In a separate bowl, whisk the flour, baking soda, baking powder, and salt until blended.

Gradually add the dry mixture to the wet ingredients. Mix just until combined to avoid tough cookies.

Fold in the oats, chocolate chips, and chopped pecans until everything is evenly distributed.

Drop dough by tablespoonfuls onto the prepared sheets, spacing scoops about 2 inches apart.

Bake for 10 to 12 minutes. Remove when edges are golden and centers still look slightly underdone.

Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.