In a food processor, combine hazelnuts and 1/2 cup of the flour. Cover and process until nuts are very finely ground. Add the remaining 1-1/2 cups flour and the baking powder. Cover and process with one on/off pulse to mix.

In a large bowl, combine butter and cream cheese. Beat with an electric mixer on medium speed for 30 seconds. Add the 2/3 cup sugar; beat until light and fluffy. Beat in egg until smooth. Add hazelnut-flour mixture, beating on low speed until smooth.

Divide dough into four portions. Shape each portion of dough into an 8-inch-long roll. Wrap in plastic wrap or waxed paper and chill about 1 hour or until firm enough to slice.

Preheat oven to 350 degrees F. Line a cookie sheet with parchment paper; set aside. Cut rolls into 1/2-inch-thick slices. Place slices 2 inches apart on prepared cookie sheet. Bake on center rack of preheated oven about 9 minutes or just until barely golden brown around the edges. Transfer to a wire rack; let cool.

Spread about 1 teaspoon of chocolate-hazelnut spread on bottom of each of half of the cookies. Top with remaining cookies, flat sides down, pressing lightly together. Makes about 32 sandwich cookies.

*Test Kitchen Tip: To toast hazelnuts (filberts), preheat oven to 350 degrees F . Spread nuts in a single layer in a shallow baking pan. Bake in preheated oven about 10 minutes or until toasted, stirring once. Place the warm nuts on a clean kitchen towel. Rub the nuts with the towel to remove the loose skins.

To Store: Layer unfilled cookies between waxed paper in an airtight container; cover. Store at room temperture for up to 3 days or freeze for up to 3 months. To serve, thaw cookies if frozen. Assemble as directed in step 5.