Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and line a 15×10-inch jelly roll pan with parchment paper.
Mix Dry Ingredients: In a bowl, whisk together the flour, cocoa powder, baking powder, and salt. Set aside.
Beat Eggs and Sugar: In a separate large bowl, beat the eggs and granulated sugar together on high speed until thick and pale, about 5 minutes.
Add Vanilla and Water: Stir in the vanilla extract and water until combined.
Fold in Dry Ingredients: Gently fold the dry ingredients into the egg mixture until just combined. Be careful not to deflate the batter.
Spread in Pan: Pour the batter into the prepared jelly roll pan, spreading it evenly.
Bake: Bake in the preheated oven for 12-15 minutes, or until the cake springs back when lightly touched.
Cool: Remove from the oven and let cool for about 5 minutes. Dust a clean kitchen towel with powdered sugar and invert the cake onto the towel. Carefully peel off the parchment paper.
Roll the Cake: Starting from one short end, roll the cake up in the towel, using it to help shape the roll. Let it cool completely while rolled.
Whip the Cream: In a mixing bowl, whip the heavy cream with powdered sugar and vanilla extract until stiff peaks form.
Unroll the Cake: Once the cake is completely cool, gently unroll it from the towel.
Spread the Filling: Spread the whipped cream filling evenly over the surface of the cake, leaving a small border around the edges.
Roll Again: Carefully roll the cake back up without the towel, starting from the opposite end this time.
Melt White Chocolate: In a microwave-safe bowl, melt the white chocolate chips in 30-second intervals, stirring until smooth.
Decorate with White Chocolate: Transfer the melted white chocolate to a piping bag or a small plastic bag with a corner snipped off. Drizzle the chocolate over the rolled cake in a spider web pattern.
Add Spider Design: Use the black decorating gel or icing to create spiders or additional web details on top of the white chocolate.
Find it online: https://succulentrecipes.com/halloween-spider-web-roll-cake/