Bake the yellow cake according to the package instructions. Let it cool completely, then cut into 1-inch cubes.

In a medium mixing bowl, whisk together the French vanilla pudding mix and cold milk according to package directions. Let it chill in the refrigerator for 30 minutes to 1 hour, until set.

For the chocolate ganache, heat the heavy cream in a saucepan over medium heat until simmering (do not boil).

Place the chocolate chips in a heatproof bowl. Pour the hot cream over the chocolate and let sit for 1 minute. Add the butter and vanilla extract.

Stir the chocolate mixture until smooth and glossy. Let it cool slightly.

In a trifle dish or large glass bowl, add a layer of cubed cake.

Spread half of the prepared vanilla pudding over the cake layer.

Drizzle a layer of the chocolate ganache over the pudding.

Repeat the layers: add another layer of cake cubes, the remaining pudding, and finish with the remaining chocolate ganache.

Loosely cover and refrigerate for at least 2 hours, or until chilled and set. The longer it chills, the better the flavors will meld.

Before serving, pipe or dollop the whipped topping around the edge of the chocolate layer. Serve immediately.