Coffee Cookies - Faxo

Ingredients

• 2 c. all-purpose flour
• 1/2 t. baking soda
• 1/2 t. salt
• 1/2 c. unsalted butter, melted and cooled*
• 1 c. light brown sugar
• 1/4 c. granulated sugar
• 1/4 c. instant espresso (or instant coffee) powder
• 1 large egg, at room temperature*
• 1 large egg yolk, at room temperature*
• 2 t. vanilla extract
• 1 c. dark chocolate (or semi-sweet), evenly chopped
• 2 T. flaky salt, for optional topping