Add butter, granulated sugar, and light brown sugar to a mixing bowl. Mix for about 5 minutes until light and fluffy. Add vanilla extract and mix until just combined.

Scrape down the sides and slowly add flour while the mixer is on low.

Once flour is mixed in, add dark chocolate chips and orange zest, mixing until combined. The dough should be smooth and dry.

Divide the dough in half and place one half on plastic wrap. Form into a circular log and roll it up in the plastic wrap. Repeat with the other half.

Chill the logs of dough in the fridge for at least 2 hours or overnight. Preheat the oven to 350 degrees when chilling time is nearly up.

Take one roll of dough out of the fridge, remove from plastic wrap, brush lightly with egg wash, and roll in turbinado sugar.

Use a sharp knife to slice cookies about 1/2 inch thick.

Place cookies on a lined baking sheet and bake for 12-14 minutes, until the edges are slightly brown. Allow to cool on the pan for 10 minutes before transferring to a cooling rack.

Garnish with orange zest and flaky sea salt. Drizzle melted dark chocolate on top if desired.

Repeat steps with the remaining dough.