1/2 Cup Butter, unsalted
1 3/4 Cup Flour
1/2 Cup Sugar
2 tsp Fresh or Dried Lavender Buds + extra for sprinkling
1 TBSP Fresh Thyme
1 Large Egg, Separated
1 tsp Salt
1 1/2 tsp Sparkling Sugar
Preheat the oven to 350°. Line cookie sheets with parchment.
Beat the butter with the oil until smooth.
Add the granulated sugar, thyme, lavender buds, and salt and beat until evenly mixed.
Beat in the egg yolk until incorporated; reserve the white.
Add the flour and mix until large clumps form. Press the clumps together into a 6-by-4-by-1-inch rectangle.
Cover tightly in plastic wrap and refrigerate until very firm, at least 1 hour.
Using a cookie cutter or preferred size glass, cut or press out circles of cookie dough and arrange onto the prepared sheets, spacing them 1 1/2 inches apart. If the dough has softened, refrigerate or freeze until firm.
Lightly brush the tops of the dough with the egg white, then sprinkle lightly with the lavender and sparkling sugar.
Bake 1 sheet at a time until the cookies are golden brown around the edges, 13 to 15 minutes. Let cool completely on wire racks.