Put the butter or margarine and confectioners’ sugar into a medium-sized bowl and beat until white and creamy.

Add the egg yolks, vanilla, lemon zest, and lemon juice. Beat well until well combined.

Add flours and mix just until it becomes a dough. Add the dried blueberries and knead until evenly dispersed.

Divide dough into two parts. Shape each part into an eight-inch (20-centimeter) log. 

Spread out the chopped pistachios on your work surface and roll each log in pistachios until well coated. Wrap each log in aluminum foil and freeze at least two hours, or until very hard.

Heat oven to 350 degrees Fahrenheit (180 degrees Celsius). Line a baking sheet with Gefen Easy Baking Parchment Paper.

Slice logs into 1/4-inch slices. Arrange in baking sheet, leaving space between the cookies. Bake for 12 minutes, or until golden. Store in an airtight container.