Directions

Cream together the butter and powdered sugar. Mix in the egg yolk.    
    
In another bowl, combine the flour, ground almonds and green tea leaf powder. Add to the first bowl and stir until the mixture forms a ball. Roll into a 2-inch-wide log. Wrap and place in the freezer for 40 minutes until firm.    
    
Preheat the oven to 350°F. Line a baking sheet with parchment paper.    
    
Roll the log in turbinado sugar to cover all sides, pressing it down a bit. Using a sharp knife cut the log into 1/4-inch slices and arrange on the prepared baking sheet.    
    
Bake for 9 minutes, or until the cookies just begin to turn golden at the edges. Let rest for 5 minutes before transferring to a rack to cool completely.