01 -
Butter and flour two 9-inch cake pans. Prepare cake batter following package instructions.
02 -
Bake cakes according to package directions. Allow cakes to cool completely.
03 -
Place one cake layer on a serving platter.
04 -
In a large bowl, using a hand mixer, combine softened butter, confectioners' sugar, marshmallow crème, vanilla extract, and kosher salt. Beat until fluffy and well incorporated.
05 -
Place the second cake layer on top of the frosted first layer.
06 -
Heat heavy cream in a small saucepan over medium heat until it just begins to bubble. Place chocolate chips in a heatproof bowl, pour hot cream over, let sit for 2 minutes, then whisk until smooth.
07 -
Pour ganache evenly over cake. Pipe a spiral of prepared frosting on top of the ganache and use a toothpick to draw spiderweb designs.