Place oven rack in middle position and heat the oven to 350℉.
In a small bowl combine 1g earl grey tea with 40g sugar, set aside for rolling.
In small saucepan over medium heat, add the butter and cook until it begins to foam and the solids become a golden color, like graham cracker crumbs. Stir frequently during this process so the milk solids do not stick to the pan.
Pour the browned butter mixture into a mixing bowl and stir in 3g earl grey tea. Allow the butter to cool until it becomes solid but spreadable (place in the fridge or over an ice bath to speed up this process).
Add the remaining 170g sugar to the butter, beat with a hand mixer on medium speed or with a spoon and lots of elbow grease for 2 minutes.
Add the egg. Beat for an additional minute to combine.
Sift in the flour, baking powder, baking soda, and salt. Fold it in with a spatula until no streaks remain.
Use a scoop to make 40g (2 Tbsp) portions of dough. Flatten each piece of dough and place a marshmallow in the center. Wrap the dough around the marshmallow into a ball, leaving just the top of the marshmallow exposed.Patch up any holes on the sides or bottom of each cookie dough ball so the marshmallow doesn't leak out and burn. Roll each ball of dough in the earl grey sugar mixture. Place cookies 2 inches apart on a baking sheet lined with parchment paper and bake for 10-12 minutes at 350℉.Pull the cookies when they just start to brown on the edges. The marshmallows will puff up in the oven then fall and set as they cool. If you overbake the cookies the marshmallows will become hard and crackled instead of soft and stretchy, so keep an eye on them! Remove from oven and cool cookies on the baking sheet for 10 minutes before transferring to cooling rack to cool completely. Store in an airtight container at room temperature for up to 3 days.The cookies are best consumed the day they are made while the marshmallows are soft and stretchy.
