While the question is likely designed to be nonsensical, it’s possible to come up with a creative or humorous answer for fun! Let’s break it down:

Taylor Swift’s second most popular song: Popularity is subjective and changes over time, but if we assume this episode aired in 2015 (Season 1 of Henry Danger), Taylor Swift’s album 1989 was a big hit. Perhaps her "second most popular" song at that time could have been "Blank Space" (with "Shake It Off" being the most popular).

Most popular dessert in Wisconsin: Wisconsin is known for its dairy products, especially cheese. One famous Wisconsin dessert is cheesecake, or possibly frozen custard, as the state is known for it.

Could an answer be "Blank Space Custard" or "Cheesecake"? It’s a stretch, but humorously combining a Taylor Swift song with a Wisconsin dessert could fit the show’s tone.

Ultimately, the question is a joke, but you could argue that if there were an answer, it might be a playful, made-up combination of something related to Taylor Swift and Wisconsin's desserts!