Prep: Sift flour, salt, and powdered sugar. Soften butter.

In a large bowl, cream softened butter and sifted powdered sugar until fluffy. Mix in vanilla.

Gradually mix in sifted flour and salt until a soft dough forms. Do not overmix.

Divide dough into two halves. In a small bowl, whisk matcha powder with warm water to a smooth paste. Mix this paste evenly into one half of the dough.

Wrap both doughs in plastic and chill for 30 minutes.

Roll out pale dough to 1/4 inch thickness. Cut out bodies using a round cutter. Roll out green dough to the same thickness. Cut out shells, flippers (4 per turtle), and heads.

Texturing: Press a waffle-pattern weaver or texture mat gently onto the green shell pieces.

Assembly: Place a pale body. Top with a green textured shell. Attach flippers and head. Press eyes gently onto the head piece.

Place assembled cookies on lined baking sheets and chill for at least 15-20 minutes before baking. Preheat oven to 325°F (165°C).

Bake for 10-12 minutes, until just set and the pale parts are no longer glossy, but not browned. Cool on sheet for 5 mins, then transfer to a wire rack.