Print the spider and web template and cut it into individual squares. Cut parchment paper into slightly larger squares and set them aside.
Melt the white and milk chocolate chips in separate bowls in the microwave or over simmering water, stirring to prevent burning. Or according to the package instructions.
Transfer the melted chocolates to two disposable piping bags or squeeze bottles.
Place a square of parchment paper over each web template and trace them with the melted white chocolate to make 12 webs (plus a few extras to account for breakage). Place in refrigerator to harden while you make the cakes.
Place a square of parchment paper over each spider template and trace them with the melted milk chocolate to make 12 spiders (plus a few extras to account for breakage). Place in refrigerator to harden while you make the cakes.
Preheat the oven to 350°F/180°C/Gas 4. Spray mini bundt cake pans with non-stick baking spray and set them aside.
Using an electric standing or hand mixer, beat the cake mix, eggs, milk, and butter until combined and smooth.
Use an ice cream scoop to divide the batter between the bundt cake cavities. Fill about ¾ full.
Bake in the preheated oven for 15-20 minutes or until an inserted toothpick comes out clean.
Remove the bundt cakes from the oven and leave to cool in the pan for 5 minutes. Then transfer to a wire rack to cool completely before decorating.
Place the chocolate chips into a medium bowl and set it aside.
Pour the heavy cream into a small pan and place over medium-low heat until simmering.
Pour the hot cream over the chocolate chips and let sit for 1 minute before whisking until smooth. Let to sit for 5 minutes, then transfer to a piping bag or squeeze bottle.
Pipe thick drips of ganache on top of each cooled bundt cake.
Carefully remove the webs and spiders from the parchment paper and place them on each cake. Add a blob of chocolate between the spider and the web to fix it in place.
Enjoy, and Happy Halloween!