Ingredients
1 cup butter, softened1-1/4 cups sugar1 large egg, room temperature1 large egg yolk, room temperature4 teaspoons instant espresso granules2 teaspoons vanilla extract2-1/2 cups all-purpose flour1/2 teaspoon salt1/2 teaspoon baking powder1 cup finely ground hazelnutsFILLING:1-3/4 cups semisweet chocolate chips, divided1-1/4 cups milk chocolate chips1 cup heavy whipping cream
Preparation
In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Beat in the egg, yolk, espresso granules and vanilla. Combine the flour, salt and baking powder; gradually add to creamed mixture and mix well. Stir in hazelnuts.
Divide dough into thirds; flatten each portion into a circle. Wrap separately; refrigerate for 1 hour or until easy to handle.
On a lightly floured surface, roll out 1 portion of dough to 1/8-in. thickness. Cut with a floured 1-1/2-in. cookie cutter; place 1/2 in. apart on ungreased baking sheets. Repeat with remaining dough; chill and reroll scraps.
Bake at 375° for 6-8 minutes or until edges begin to brown. Remove to wire racks to cool.
For filling, place 3/4 cup semisweet chocolate chips and milk chocolate chips in a small bowl. In a small saucepan, bring cream just to a boil. Pour over chocolate; whisk until smooth. Refrigerate until filling reaches spreading consistency, about 1-1/2 hours, stirring occasionally.
Spread filling over the bottoms of half of the cookies; top with remaining cookies. In a microwave, melt remaining 1 cup semisweet chips; stir until smooth. Drizzle over cookies. Let stand until set. Store in an airtight container in the refrigerator.
