Mocha Cookie Sandwiches

1. In a medium bowl, combine flour, cocoa powder, espresso powder, baking powder, baking soda, and salt. Set aside.

2. In a large bowl, beat butter with an electric mixer on medium speed for 30 seconds. Add sugar. Beat until combined, scraping side of bowl occasionally. Add egg, melted chocolate, and vanilla; beat until combined. Beat in as much of the flour mixture as you can with the mixer. Using a wooden spoon, stir in any remaining flour mixture.

3. Divide dough into thirds. Shape each portion into an 8-inch-long log. Roll each log in pecans, pressing gently so pecans stick. Wrap each log in plastic wrap. Chill about 2 hours or until firm.

4. Preheat oven to 375 degrees F. Cut logs into 1/4-inch-thick slices. Arrange slices 1 inch apart on an ungreased cookie sheet. Bake for 8 to 10 minutes or until edges are set. Cool on cookie sheet for 1 minute. Transfer cookies to a wire rack; cool.

5. Spread some of the Coffee Buttercream on the bottom of a cookie. Top buttercream filling with another cookie, bottom side down, to make a sandwich cookie. Repeat with remaining cookies and Coffee Buttercream. Makes about 32 sandwich cookies.

Coffee Buttercream: In a large bowl, combine 2-1/2 cups sifted powdered sugar; 1/2 cup butter, softened; and 2 tablespoons coffee liqueur or strong brewed coffee. Beat with an electric mixer on medium speed until combined. Increase speed to high and beat for 1 minute more, scraping side of bowl as necessary.

To Bake Ahead: Prepare, bake, cool, and fill cookies as directed. Layer cookies between waxed paper in an airtight container. Cover; seal. Store at room temperature for up to 3 days. Or freeze unfilled cookies for up to 3 months. Thaw cookies; fill with Coffee Buttercream.