Heat oven to 350 degrees F.

Spread pistachios on baking sheet and toast in oven for about 7 minutes, until aromatic, but not browned. Cool, and then grind in food processor to a coarse meal.

In mixing bowl, add flour, salt, green tea powder and pistachio meal.

In separate bowl or stand mixer, cream butter, add 1/2 cup of powdered sugar and continue to beat for a few minutes until creamy and smooth. Blend in the vanilla extract and optional food color. I recommend using the gel mentioned in the ingredient list because it's much easier to control the amount of color. I just use a toothpick to blend a tiny bit of color.

Slowly add the dry mixture until blended.

With your hands, roll 1 teaspoonful of dough in your hands and place on baking sheet about 2 inches apart. The sheet doesn't have to be lined with parchment paper. Repeat until dough is used up.

Bake for about 17 minutes until cookie sets and the bottom is slightly golden. Cool completely on wire rack.

Roll in powdered sugar.