In a medium mixing bowl, whisk together the flour and salt until evenly distributed.

Using a stand mixer fitted with the paddle attachment, cream the softened butter and granulated sugar on medium-high speed until pale and fluffy, approximately 3 to 4 minutes.

Add the egg, vanilla extract, lemon zest, and ground lavender; continue mixing until fully incorporated.

Reduce the mixer speed to low and gradually add the flour mixture, mixing only until no dry streaks remain.

Wrap the dough in plastic film and refrigerate for 30 to 45 minutes to firm up.

Preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper.

Form the chilled dough into 1-inch spheres and place them 2 inches apart on the baking sheets.

Bake for 10 to 12 minutes, or until the edges are very lightly browned while the centers remain pale.

Transfer the cookies to a wire rack to cool completely.

In a small bowl, whisk the confectioners' sugar and lemon juice until a smooth, pourable glaze forms.

Drizzle the glaze over the cooled cookies and allow it to set for 20 minutes before serving.