These recipes are from the Mondseer Kochbuch, which was written in the mid 16th C at the Benedictine monastery in Mondsee, Austria. These are the modern German transcriptions from Speisen wie de Äbte und esse wie die Mönche, by Arnold Nauwerck, published in 1998.
40. Wie Man gute Krapfen macht
Willst du eine gescheite Speise machen, so mache einen Tieg aus Eiern und Weißmehl und dicke ihn mit geriebenem Weißbrot. Schäle saure Äpfel und schabe sie größer als Speck zu Hühnern. Mische alles zusammen. Gib die Maße löffelweise in die Pfanne, breite sie mit dem Löffel aus und brate sie in Schmalz oder, falls es kein Fleischtag ist, in Butter und serviere sie.
How to make good Doughnuts
If you want to make a sensible dish, make a bowl out of eggs and white flour and thicken it with grated white bread. Peel tart apples and scrape them larger than bacon on chickens. Mix everything together. Spoon the measurements into the pan, spread them out with the spoon and fry them in lard or butter if it’s not meat day and serve.
This transcription varied somewhat from the next recipe, so I went back to the original German, and double-checked it with Volker Bach, who translates recipes from the original German texts all the time. He thinks the instructions should be interpreted as more like a ravioli recipe, putting the filling into a dough that has been separated. I tried that with a couple, but also did some as if they were more like pirogies, so I could have a thinner dough and more filling.
41. Wie Man Krapfen mit Käse und Speck macht
Reibe Käse, mische ihn mit Eiern und schabe gekochten Speck dazu. Mache einen derben Teig, fülle ihn damit und mach Kräpflein. Backe sie, je nach der Zeit (ob Fasttag oder Fleischtag) in Butter oder in Schmalz und serviere.
How to make donuts with cheese and bacon
Grate cheese, mix it with eggs and shave cooked bacon on top. Make a rough dough, fill it with it and make donuts. Depending on the time (fast day or meat day), bake them in butter or lard and serve.
I fried mine, rather than baking, as I believe it is a more accurate translation.
I used a jumbo egg, about 3/4 c of white flour, and some crushed breadcrumbs to make a dough. I divided it into eight pieces and rolled most of them out. I reserved two to test stuffing more of a ball shape. The apple I used wasn’t particularly sour. I only needed half of one to make four krapfen. I cooked one slice of bacon and chopped up about 1 1/2 oz of cheese for the second batch of four. I cooked them in approximately 2 Tbsp of chicken fat. It was really tempting to combine some of the apple filling with the cheese and bacon.