This is an excerpt from Das Kuchbuch der Sabina Welserin
(Germany, 16th century - V. Armstrong, trans.)
The original source can be found at
David Friedman's website
108 If you would make a white tart. Take egg whites and pour a pint of cream thereon, and let it cook in a pan until it thickens, and put rose water in it and spread it out, then it is good.
Recipes with similar titles:
To Make a White Torte (The Neapolitan recipe collection)
White Tart (The Neapolitan recipe collection)