1 package Devil's food cake mix
Vegetable cooking spray
4 cups Powdered sugar -- sifted
5 to 7 tablespoons Milk
1 cup Powdered sugar -- sifted
1/4 cup Unsweetened cocoa
2 tablespoons Milk
Prepare cake as directed on package. Pour into 2, 8" square aluminum foil pans coated with cooking spray; bake at 350 for 30-35 minutes or until tested done.
Cool in pans on wire racks. Combine 4 cups powdered sugar and 5-7 Tbsp milk in a large bowl; spread a thin layer evenly over each cake.
Combine 1 cup powdered sugar, cocoa and 2 Tbsp milk; spoon into a small zip-lock bag. Close bag securely and snip a tiny hole in bottom corner of bag.
Carefully pipe concentric circles onto each cake. Pipe straight lines at intervals from the inner circle through the outside circle, forming a web design.
Garnish with plastic spiders.