1. Preheat the oven to 375F. Line several baking sheets with foil.
2. Using a mixer on medium, beat the butter and sugar until creamy, about 2 minutes. Beat in the flour, egg and zest until a dough forms. Fill a pastry bag fitted with a large round writing tip with the dough.
3. Pipe three 4-inch lines in a cross pattern onto a prepared baking sheet. Pipe lines connecting the points and centers of the lines of the cross to create a web pattern. Repeat to make more webs.
4. Bake the cookies until set but not yet browned, about 8 minutes. Cool the baking sheets on wire racks 1 minutes. Transfer the cookies to the racks to cool completely.
5. Fill a small resealable plastic bag with the melted chocolate; snip off one corner. Attach a candy-coated chocolate piece on top of a web cookie for a “spider” using melted chocolate; pipe on spider “legs.” Attach orange nonpareils for the “eyes” of the spider using melted chocolate.
Tip
These cookies are fragile: Take special care when lifting them off the baking sheets. Use an offset spatula the width of the cookie to keep them from breaking.