Baker's malt extract is different from brewer's malt extract. I think you can use the brewing stuff for baking, but not the baking stuff for brewing. That said, I suspect a light malt extract would make a basic, classic pretzel, while you would get darker pretzels and more complex and roasty flavors from darker malt extracts. Approach the pretzels like a beer recipe and you should be able to control your output in a similar way.
Primary: Orange Peel JAOM, Orange Rind JAOM, Pomelo Rind JAOM, IIPA
Bottled: Holy Ester! Caramel Amber Ale, Left Hand Milk Stout Clone, All-Mosaic IPA, Pu-er Pale Ale
Coming Up: Maybe a nice porter?
Other: 米酒 (traditional Chinese rice wine); Sauerkraut