Get the recipe for Chef John's Sourdough Starter.
If you don't have sourdough starter, mix 3/4 cup flour with about 1/3 cup cold water, or enough to simulate the thickness of the one seen in the video, and add a pinch (1/16 teaspoon) of yeast. Mix, cover and leave overnight until bubbly and risen, just like the one in the video.
You'll find the panettone baking molds in kitchenware stores at the mall, but they're also inexpensive and easy to find online. You'll see both in this size as well as the more traditional, tall, coffee-can shape.
I may add a bit more vanilla next time, and possibly a few extra tablespoons of sugar, as it wasn't quite as sweet as I imagined, but other than using all the fruit, I don't think I'd change much else.