Melt 1 cup of unsalted butter in a small saucepan. Add 2-3 Earl Grey tea bags or 2 tablespoons of finely ground Earl Grey tea. Infuse for 5 minutes, then strain the tea leaves.

In a large bowl, mix 3/4 cup brown sugar and 1/2 cup granulated sugar. Add the cooled Earl Grey butter, 1 large egg, 1 egg yolk, and 2 teaspoons vanilla extract. Mix until creamy.

In a separate bowl, whisk 2 cups all-purpose flour, 1/2 teaspoon baking powder, 1/2 teaspoon baking soda, 1/4 teaspoon salt, and 1 tablespoon ground Earl Grey tea until combined.

Gradually add the dry ingredients to the wet mixture and mix gently. Fold in 1 cup of chopped dark chocolate until evenly distributed.

Cover the dough with plastic wrap and chill in the refrigerator for at least 30 minutes. Preheat oven to 350°F (175°C).

Scoop tablespoon-sized balls of dough onto a lined baking sheet, 2 inches apart. Optionally sprinkle with flaky salt. Bake for 10-12 minutes until edges are set.

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