Into the bowl of a stand mixer or using an electric hand mixer, add softened butter, granulated sugar, and brown sugar. Mix on medium speed until combined, 2-3 minutes. Turn off mixer, scrape down sides of bowl, and mix again for 2 minutes. Mixture should be light and fluffy.
Add the eggs, one at a time, and beat for an additional 2 minutes until well incorporated. Pour in vanilla extract and mix for an additional minute.
Add flour, baking soda, and salt. Mix on low speed until flour is almost absorbed. Remove bowl from stand mixer and use a rubber spatula to mix in chocolate chips and pecans by hand.
Cover bowl and chill dough mixture for at least 1 hour or up to 48 hours.
Preheat oven to 350 degrees F. Line two baking sheets with parchment paper. Using a cookie scoop, place 1 tablespoon-sized balls onto baking sheet. Sprinkle with flaky sea salt (if using).
Bake for 10-12 minutes, until the edges become a light golden brown.
Let cookies rest on baking sheet for 10 minutes before transferring them to a cooling rack. Store in an airtight container for up to 5 days.