Oatmeal Chocolate Chip Cookies — Samantha Chen Bakes

Ingredients

• ¾ cup unsalted butter, melted
• 1 cup light brown sugar, packed
• 1 large egg, room temperature
• 1 egg yolk, room temperature
• 2 tsp vanilla extract
• 1½ cups all-purpose flour
• ¼ tsp baking soda
• Pinch of salt
• 1 cup old-fashioned oats
• ¾ cup semisweet chocolate chips
• ¾ cup chopped chocolate bar (optional)
• Flaky sea salt, for topping (optional)