OVERALL: if I could only have one dessert in Pittsburgh, I would choose a Waffallonia waffle. There are a variety of toppings available, and best of all, they go on top of a sugary, warm, crispy waffle that may be the best waffle I've ever eaten in my life. Waffles can get a bit expensive, but can be shared between 2 people.
Whenever my friends come visit Pittsburgh, they ask me for food recommendations. Depending on their tastes, I recommend a few restaurants that I think they'll like. However, I always make sure to recommend Waffallonia to everyone - that's how good it is.
The waffles here are the highlight, not the toppings. While the toppings are certainly fresh and tasty, nothing can compare to how amazing the waffles are. They have just the right amount of sugar to be sweet, but not overly so, and are cooked perfectly - crispy on the outside, but chewy once you bite into the warm, delicious inside. I've never had a bad waffle at Waffallonia, and I've been here at least 10 times, so they are very consistent as well. As for toppings, you can choose fruits (strawberries/bananas), ice cream (their speciality is the speculoos flavor), nutella, and chocolate sauce.
I don't know how Waffallonia does it, but I do know that I have to convince myself to not come here twice a week, lest I die from excessive sugar consumption. You MUST try this place!