In a medium bowl, whisk together the flour and salt. Set aside.
In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
Beat in the egg and vanilla extract until well combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
Gently fold in the chopped lavender buds and matcha powder until evenly distributed.
Cover the dough and chill in the refrigerator for at least 30 minutes.
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
Roll the dough into 1-inch balls and place them on the prepared baking sheets, spacing them about 2 inches apart. Flatten each ball slightly with the palm of your hand or the bottom of a glass.
Bake for 10-12 minutes, or until the edges are lightly golden.
Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.
Notes
Store in an airtight container at room temperature for up to 3 days.