You could say it started with the medical community.

You see, Germanys harsh climate and inland population led to the almost non existence of foodstuffs enjoyed in the Mediterranean, things ubiquitous to the Mediterranean like citrus, olives and fish were very uncommon in Germany.

However, during the medieval times most German physicians went to Italy to study and train in medicine in the famous schools of Salerno, Montpellier, or Bologna, during this time they'd be under the influence of Italian and Arab influenced cuisine. In this time they'd translate it to their latin texts and bring it back to Germany (although mostly for health reasons).

During the 14th century two of these physicians , Konrad von Eichstät and Arnold von Bamberg added to one of the scripts of health and sanitation at the time, the Regime Sanitatis. Of these physicians, the most prolific was a man named Arnold von Bamberg[169]

Arnolds regime[The regimen sanitatis of Arnold von Bamberg] contains an impressive 40 recipes, mostly French and Italian, he explains how common the use of salt, vinegar and verjuice (a type of grape based, lightly acidic vinegar) is in cooking, how they made doughs, fried food, etc. On his chapter on cheese he listed the recipes of 3 Italian classics, lagana(lasagna), rafioli(ravioli) and tarte(pie). [170]

This leads us to believe that it may have been German physicians during the medieval period that had introduced Germany to pastas. I hope I answered your question, as it's been fun digging into the cause of German food from the time. Sorry for the wall of text.

[Food in medieval times, Melita Weiss Adamson.169. Adamson, Medieval Dietetics, 142–9, and 150–60; see also chapter 6. ]

[Food in medieval times, by Melita Weiss Adamson.170. edition of Ortolf’s regimen is contained in Karin Figala, “Mainfränkische Zeitgenossen ‘Ortolfs von Baierland’: Ein Beitrag zum frühesten Gesundheitswesen in den Bistümern Würzburg und Bamberg” (Pharm. diss., University of Munich, 1969), 160–90