Preheat the oven to 320℉ (160℃) and line a baking sheet with parchment paper.
In a mixing bowl, combine softened butter, powdered sugar, and salt using a spatula or whisk until no white powdered sugar remains visible.
4 ounces unsalted butter, ⅔ cup powdered sugar, ¼ teaspoon salt
Add the egg yolks and mix until evenly combined.
2 medium size egg yolks
Stir in the Earl Grey tea powder, whipping cream, lemon juice, and lemon zest, mixing until well combined.
2 packets Earl Grey tea from tea bags, 1 ¼ tablespoons whipping cream, 2 teaspoons lemon juice, ½ tablespoon lemon zest
Sift cake flour and almond flour into the bowl, then gently fold it into the butter mixture using a cut-and-lift motion until just incorporated (do not overmix!).
1 cup cake flour, ½ cup almond flour
Transfer the cookie mixture to a piping bag fitted with a piping tip and pipe rosettes onto the prepared baking sheet.
Bake for 15 minutes, then let the cookies cool completely.
While the cookies bake, prepare the lemon glaze by mixing ¼ cup powdered sugar with 4 tablespoons lemon juice in a small bowl until thick yet pourable.
4 tablespoons freshly squeezed lemon juice, ¼ cup powdered sugar
Once the cookies have cooled, drizzle or dip them in the lemon glaze, then allow the glaze to set before serving.