In a medium bowl, whisk together the dry ingredients: flour, baking powder, baking soda, salt, and Earl Grey tea leaves. Set aside.

In a large bowl, beat the butter with granulated and brown sugars until light and fluffy.

Add the egg and vanilla to the creamed mixture and mix until fully incorporated.

Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined. Chill the dough for 15 minutes.

Preheat oven to 350°F (175°C). Scoop tablespoon-sized balls of dough, roll in sugar, and place on prepared baking sheet.

Bake for 11-12 minutes until edges are golden but centers are slightly underdone.

Cool cookies on the baking sheet for about 10 minutes before transferring to a wire rack.

Prepare the glaze by whisking together powdered sugar and lemon juice until smooth. Drizzle over cookies once cooled.

Allow the glaze to set for at least 10 minutes before serving.