Bake the yellow cake in a 9×13-inch pan according to package directions. Let cool slightly.

Using the handle of a wooden spoon, poke holes all over the warm cake.

In a bowl, whisk pudding mixes with cold milk until smooth and thickened.

Pour pudding evenly over the cake, spreading with a spatula to fill holes.

Chill cake in the fridge for 1 hour to set.

In a microwave-safe bowl, heat heavy cream until hot (but not boiling). Add chocolate chips and let sit 2 minutes, then stir until smooth.

Pour chocolate ganache over chilled cake and spread evenly.

Refrigerate cake for another hour or until chocolate is set.

Slice and serve chilled.