01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, ground Earl Grey tea, baking powder, and salt. Set aside.
03 - In a large bowl, cream the softened butter and 1 cup sugar together until light and fluffy, about 2 minutes.
04 - Beat in the egg, vanilla extract, lemon zest, and lemon juice until well combined.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until incorporated. Do not overmix.
06 - Scoop tablespoon-sized amounts of dough and roll into balls. Roll each ball in the extra granulated sugar and place on the prepared baking sheets, spacing about 2 inches apart.
07 - Flatten each ball slightly with the bottom of a glass or your palm.
08 - Bake for 11–13 minutes, or until the edges are just beginning to turn golden.
09 - Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.