In large food processor bowl, combine cookies and the 3/4 cup pecans. Cover and process with on/off turns until cookies are crushed. Add orange liqueur, cocoa powder, and corn syrup. Cover and process until combined.
Line a large baking sheet with parchment paper. Shape cookie mixture into 1-inch balls. Place balls on prepared baking sheet; insert a lollipop stick into each ball. Freeze for 30 minutes.
In a small saucepan, stir chocolate pieces and shortening over medium-low heat just until mixture is melted and smooth. Remove from heat. Spoon the melted chocolate over cookies. If desired, sprinkle with toasted coconut, nonpareils, and/or finely chopped pecans. Loosely cover and chill about 1 hour or until chocolate is set. If pops contain orange liqueur, the flavor will mellow in a few days.
Place pops in a single layer in airtight container; cover. Store in the refrigerator for up to 7 days.