Description
A quarter-sheet black cocoa sheet cake frosted in mostly white buttercream, decorated with an easy spiderweb draw-and-drag technique and finished with 1–2 candy spiders.
Ingredients
- All-purpose flour: 1 1/2 cups (190 g)
- Black cocoa powder: 1/2 cup (50 g)
- Baking powder: 2 tsp (8 g)
- Baking soda: 1/2 tsp (2 g)
- Fine salt: 1/2 tsp (2.5 g)
- Granulated sugar: 1 cup (200 g)
- Unsalted butter, softened: 1/2 cup (113 g)
- Large eggs: 3
- Vanilla extract: 2 tsp (10 ml)
- Buttermilk: 3/4 cup (180 ml)
- Hot coffee (or hot water): 1 cup (240 ml)
- Neutral oil (for extra moisture): 2 tbsp (30 ml)
- Red gel color (optional, for a slightly warmer “black” look): 1 to 2 drops
- Mostly-white buttercream: Unsalted butter, softened: 1 cup (227 g)
- Powdered sugar: 4 cups (480 g)
- Fine salt: 1/4 tsp (1.5 g)
- Vanilla extract: 2 tsp (10 ml)
- Milk or heavy cream: 3 to 6 tbsp (45 to 90 ml)
- Optional: black cocoa powder for darker web lines: 1 to 2 tsp (2 to 4 g)
- Candy spiders: 1 to 2
Instructions
- Prep: Heat oven to 350°F (175°C). Grease a 9×13 in (23×33 cm) baking pan and line the bottom with parchment. Lightly grease the parchment.
- Mix dry: In a large bowl, whisk flour, black cocoa, baking powder, baking soda, and salt until no lumps remain.
- Mix wet: In a separate bowl (or stand mixer), beat butter and sugar until fluffy, about 2 minutes. Beat in eggs one at a time, then mix in vanilla, buttermilk, and oil. If using, add red gel drops and mix until evenly streaked (don’t overmix).
- Combine: Add dry ingredients to wet in 2 additions, mixing just until smooth. With mixer on low, slowly pour in hot coffee (or hot water). Batter will look thin—this is normal.
- Bake: Pour batter into prepared pan. Bake 30 to 38 minutes, until the center springs back and a toothpick inserted near the center comes out with a few moist crumbs (not wet batter).
- Cool completely: Cool in pan 10 minutes, then lift out using parchment and cool fully on a rack, about 1 hour. Do not frost warm cake—your web will smear.
- Make mostly-white buttercream: Beat butter until smooth. Add powdered sugar and salt in 2 to 3 additions, mixing on low at first. Add vanilla. Slowly stream in milk/cream until you reach a smooth, spreadable consistency (it should hold shape and spread with a gentle smear).
- Optional darker web lines: If you want slightly darker grooves, set aside 2 to 4 tbsp of buttercream and stir in 1 to 2 tsp black cocoa. Keep the rest mostly white.
- Frost: Spread buttercream over the cooled cake. Aim for an even, smooth top. If you see ridges, gently smooth with an offset spatula.
- Chill briefly: Refrigerate 10 to 20 minutes so the frosting firms up for clean drawing.
- Draw the spiderweb: Working from the center out, lightly trace concentric circles on the top using the back of a spoon (or a fork). Then, starting at the center, pull thin radial lines outward. Rotate the cake so the lines are evenly spaced. If lines look too faint, press only slightly more—don’t dig.
- Place spider topper: Add 1 to 2 candy spiders at the center (or one corner) right after finishing the web.
- Serve: For the crispest look, serve within the hour. If the room is warm, chill 10 minutes right before serving.
Notes
If your web grooves blur, the buttercream is too soft—chill longer and draw again with lighter pressure. For the strongest contrast, keep most of the buttercream very pale and use darker cocoa only for optional deepened grooves.