Makes about 3 dozen cookies.

Note: Our 2010 winner is from Scott Rohr of Minneapolis.

For cookies:

• 2 c. flour

• 1 tsp. salt

• 2 tsp. cream of tartar

• 1 tsp. baking soda

• 1 c. (2 sticks) butter, at room temperature

• 1/2  c. granulated sugar, plus extra for rolling dough

• 1/2  c. firmly packed brown sugar

• 1 egg

• 1 tsp. vanilla extract

For filling:

• 1 c. raw shelled pistachios, divided

• 1/2 c. (1 stick) butter, at room temperature

• Freshly grated zest of 1 orange, finely chopped

• 1 tsp. orange extract

• 1 tsp. vanilla extract

• 3 c. powdered sugar

• 2 tbsp. milk (or use 1 tbsp. milk and 1 tbsp. freshly squeezed orange juice)

Directions

To prepare cookies: Preheat oven to 350 degrees and line baking sheets with parchment paper.

In a large bowl, whisk together flour, salt, cream of tartar and baking soda and reserve. In a bowl of an electric mixer on medium-high speed, beat butter, granulated sugar and brown sugar until light and fluffy, about 2 minutes. Add egg and vanilla extract and mix until thoroughly combined.

Reduce speed to low and add flour mixture, in thirds, mixing until just combined. Form dough into 1/2-inch balls (about the size of a chestnut).

Roll dough balls in granulated sugar and place 2 inches apart on prepared baking sheets. Bake until cookies are set but not browned, about 11 minutes (cookies will puff up in oven, but flatten).

Remove from oven and let cool on baking sheets for 2 minutes, then transfer to a wire rack to cool completely.

To prepare filling: In food processor fitted with a metal blade, pulse 1/2  cup pistachios until very fine (the nuts should almost clump together in a paste between your fingers).

In a bowl using an electric mixer on medium-high speed, beat butter with orange zest until light and fluffy. Add orange extract and vanilla extract and mix until thoroughly combined.

Reduce speed to low and add powdered sugar, in thirds, alternating with milk (or milk and orange juice), beginning and ending with powdered sugar, and beat until smooth (you may need another tablespoon or so of liquid to reach desired consistency). Fold in pistachios, mixing until thoroughly incorporated.

To assemble cookies: Finely chop remaining 1/2 cup pistachios and place in a shallow dish. Spread a generous dollop of filling on the flat side of one cookie. Place the flat side of a second cookie against filling, making a sandwich. Press gently just until filling is at edge of cookies. Roll filled edge in chopped pistachios. Repeat with remaining cookies.