01 -
Grease and flour two 23-centimetre round cake pans. Mix the chocolate cake batter as directed on the packaging.
02 -
Pour batter evenly into prepared pans. Bake following package instructions. Allow cakes to cool completely in the pans on a wire rack.
03 -
Once cooled, invert one cake onto a serving platter.
04 -
In a large bowl, beat together the softened butter, confectioners' sugar, marshmallow crème, vanilla extract, and kosher salt using a hand mixer until light and fluffy.
05 -
Spread a portion of the marshmallow frosting over the base layer, then place the second cake on top.
06 -
In a small saucepan, heat heavy cream until just beginning to simmer. Pour over semisweet chocolate chips in a heatproof bowl. Let stand for 2 minutes, then whisk until glossy and smooth.
07 -
Pour ganache over the stacked cake, allowing it to cover the top and drip down the sides. Pipe a spiral of vanilla icing on top and drag a toothpick from the centre outward to create a spiderweb pattern.