To make the chocolate spiderwebs, melt the chocolate candy melts according to the package instructions until smooth.
Pour into a disposable piping bag and cut off the tip.
Pipe half spider webs onto a cookie sheet lined with wax paper: pipe a horizontal line, then a vertical line connecting to the horizontal one, and two diagonal lines connecting to the middle of the horizontal one where the vertical one meets. Then connect each of the lines with half circles. If you are not confident with piping freehand, you can draw the web design on the reverse of the wax paper, or print a spider web design onto a piece of paper and place it under the paper to trace on top of.
Leave to set overnight in a cool, dry place.
For each spider, pinch off a ½ teaspoon size piece of fondant, and a ¼ teaspoon size piece of fondant. You will need 12 of each size in total, plus a few extras, just in case!
Roll fondant pieces into balls.
Dip your finger lightly into some water and wet one of the fondant balls so that you can stick them together. Place each spider on cookie sheet lined with wax paper and leave to dry in a cool, dry place overnight.
To make the cupcakes, preheat oven to 180C/350F/Gas 4 and line a cupcake pan with 12 cupcake liners.
Place all of the cupcake ingredients in a medium bowl and mix to combine.
Fill cupcake liners three-quarters full.
Bake for 21 minutes or until an inserted toothpick comes out clean.
Leave in pan to cool for 5 minutes, before transferring to a wire rack to cool completely before frosting.
To make the frosting, use an electric stand or handheld mixer.
Place all the ingredients in a bowl and mix on medium speed until smooth and creamy and peaks form.
Transfer to a piping bag fitted with a star tip.
Pipe swirls of frosting onto each cooled cupcake.
Carefully peel spider webs from wax paper and insert one into each of the frosted cupcakes towards the back.
Place a spider in the center of each cupcake, in front of the web.
Use the tube of black icing to pip out spider legs.
Leave to set for about 10 minutes before serving.