Prepare for Baking: Preheat your oven to 180°C (350°F) or gas mark 4. Line a cupcake tray with paper liners.
Make the Cupcake Batter: In a food processor, mix the caster sugar, softened butter, egg, vanilla bean paste (or extract), and peanut butter until the mixture is light, smooth, and fluffy.
¼ cup caster sugar, ¼ cup unsalted butter, 2 tablespoons peanut butter, 1 large egg, ½ teaspoon vanilla bean paste or extract
Add the plain flour, baking powder, fine sea salt, and milk to the same container, then blend until smooth. Fold in the chocolate chips and pulse briefly—some may break apart, adding a touch of color, while most stay whole for a bit of crunch.
1 cup plain flour, 1 teaspoon baking powder, ¼ teaspoon fine sea salt, ½ cup whole milk, ½ cup chocolate chips
Bake the Cupcakes: Scoop the batter evenly into the 12 lined cupcake liners, filling each about two-thirds full. Bake in the preheated oven for 15-18 minutes, or until a toothpick inserted into the center of a cupcake comes out clean. Once baked, remove the cupcakes from the oven and let them cool completely on a wire rack to avoid sogginess.
Prepare the Royal Icing: In a small bowl, combine the caster sugar, egg white, and a few drops of lemon juice. Mix until the icing is smooth and glossy. This royal icing will be used to create the spider web design, so set it aside for later.
½ cup caster sugar, 1 egg white, 2-3 drops lemon juice
Make the Frosting: In another bowl, beat the softened unsalted butter, icing sugar, cocoa powder, and whipping cream together until the mixture is fluffy. This usually takes about 3-5 minutes. Add the natural vanilla extract and the black food coloring paste, mixing until you achieve the desired color.
⅓ cup unsalted butter, ½ cup icing sugar, ¼ cup cocoa powder, ¼ cup whipping cream, ½ teaspoon vanilla extract, 1 teaspoon black food coloring paste
Decorate: Spread a generous layer of the chocolate frosting on top of each cooled cupcake using a spatula or a knife. For the finishing touch, transfer the royal icing to a piping bag. Pipe small circles starting from the center of each cupcake, then connect the circles with thin lines to create a spider web effect. Let the icing set for a few minutes before serving.
Video
Notes
Room Temperature Ingredients: Make sure your butter, egg, and milk are at room temperature.
Peanut Butter Choice: I like using creamy peanut butter for a smooth batter, but if you prefer a little crunch, chunky peanut butter works too!
Royal Icing Consistency: Add lemon juice slowly, one drop at a time, until the icing is thick but still easy to pipe for those spider webs.
Chocolate Chips: A little tip—toss your chocolate chips in a bit of flour before adding them to the batter to stop them from sinking to the bottom.
Substitutions: If you need nut-free cupcakes, swap the peanut butter for sunflower seed butter or leave it out altogether. You can also use almond or oat milk instead of whole milk.