Preheat Oven: Preheat your oven to 350°F (175°C). Line a cupcake tin with paper liners.

Prepare Cupcake Batter: In a large bowl, sift together flour, sugar, cocoa powder, baking powder, baking soda, and salt. In another bowl, mix together the buttermilk, vegetable oil, eggs, and vanilla extract until well combined. Gradually add the wet ingredients to the dry ingredients, mixing well. Carefully stir in the boiling water. The batter will be thin.

Bake Cupcakes: Pour the batter into the lined cupcake tin, filling each about two-thirds full. Bake in the preheated oven for about 18-20 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool completely on a wire rack.

Create Spiderweb Decorations: Melt the white chocolate chips in a microwave-safe bowl, stirring every 20-30 seconds until smooth. Transfer the melted chocolate into a piping bag with a small round tip. Pipe a simple spiderweb design onto each cooled cupcake. Start with a small spiral and then connect lines from the center to the edges.

Decorate: Once the spiderwebs are set, place a plastic spider on each cupcake for a spooky effect (optional).