Christmas markets are a holiday tradition in the German-speaking part of Europe that date back to the Middle Ages. So the best Christmas markets, known locally as 
Christkindlmarkt or 
Weihnachtsmarkt, are definitely in Germany. While the markets originated in Germany, they can now be found in many other regions of Europe and among German communities in North America. I got to visit the one in Chicago when I was at Purdue.
During the pandemic, I got to visit several in Germany including the Weihnachtszauber in Gendarmenmarkt and the City-Weihnachtsmärkt at Gedächtniskirche (Kaiser Wilhelm Memorial Church), both in Berlin.
Of course, I went there for the food and the 
Glühwein (mulled wine), especially 
Feuerzangenbowle (rum-soaked sugarloaf set on fire and dripped into mulled wine). 
At one of the markets, I had 
Lángos, a deep-fried flatbread that originated from Hungary. I had a simple one topped with butter and garlic. Others are topped with cheese and vegetables.
I also had 
Handbrot (hand-rolled flatbread) topped with sour cream, bacon, and spring onions.
The 
Handbrot is baked in a wood-fired oven.
Of course, there are pretzels and sausages. I had a 
Rostbratwurst.
I also got to visit two Christmas markets in Köln (Cologne). Super crowded despite the pandemic!
At the Weihnachtsmarkt in Aachen, I got to try 
Reibekuchen (potato pancakes).
Aside from food, you can also get Christmas arts and crafts at the markets.
In Hamburg, we dropped by the Santa Pauli Hamburgs Geilster Weihnachtsmarkt, the Christmas market of Hamburg's red light district.
I got to try 
Grünkohl (kale) with 
Kohlwurst, 
Bärlauch-Hacksteak (hamburger steak), 
Currywurst, and 
Flammkuchen (tarte flambée).
For drinks, I got 
Eierpunsch (egg punch) made with delicious 
Eierlikör (egg liqueur) and white wine. While it is sometimes referred to as the German version of eggnog, the difference is that 
Eierpunsch is made with wine while eggnog is made with milk.
And since it was Christmas, we got some Plätzchen (Christmas cookies) from one of the bakeries in Ulm!
What's your favorite food at German Christmas markets?