Melted butterscotch candy fills the cutouts in these spooky chocolate cookies.
Whisk together flour, cocoa powder, and salt. Beat butter with sugar on medium-high speed until pale and fluffy. Beat in eggs, 1 at a time, then vanilla. Reduce speed to low; gradually add flour mixture. Divide dough in half; form each half into a disk and wrap each in plastic. Refrigerate until firm but still pliable, about 1 hour.
Preheat oven to 350 degrees. Working with one disk at a time on lightly floured parchment, roll out dough 1/4 inch thick. Brush off excess flour; transfer dough on parchment to a baking sheet and freeze until firm, about 15 minutes. Cut into 4 1/2-inch pumpkin shapes with cookie cutters, rerolling scraps as needed. Transfer cookies to parchment-lined baking sheets; cut faces with the tip of a sharp paring knife. (If dough starts getting too soft, freeze 10 minutes.) Freeze until firm, about 15 minutes. Bake, rotating once, until just set, 12 minutes. Remove from oven; fill cutouts with crushed candy. Bake again until cookies begin to brown at edges and candy is melted, 3 minutes. Let cool completely on sheets on wire racks.