Fine Powder, also known as Sweet Powder or Poudre Douce, is one of the spice blends that seems to be prominent in the culinary recipes recorded during the Middle Ages. Although each cook might personalize the blend to his own taste; there appears to be two ingredients that make the blend a "Fine Powder": Sugar and Ginger.
In Le Menagier de Paris there is a recipe for Fine Powder.
Prenez gingembre blanc (une once et une drachme?) canelle triée (un quarteron?) giroffle et graine de chascun demi quart d'once, et de succre en pierre (un quarteron?) et faictes pouldre .
Translation by Janet Hinson:
Fine Powder of spices
Take an (ounce and a drachma?) of white ginger, a (quarter-ounce?) of hand-picked cinnamon, half a quarter-ounce each of grains and cloves, and (a quarter-ounce ?) of rock sugar, and grind to powder.
In Libro di cucina/ Libro per cuoco there is a recipe for Sweet spices, enough for many good and fine things .
Specie dolce per assay cosse bone e fine.
Le meior specie dolze fine che tu fay se vuoi per lampreda in crosta e per altri boni pessi d'aque dolze che se faga in crosto e per fare bono brodetto e bon savore. Toi uno quarto de garofali e una onza de bon zenzevro e toy una onza de cinamo leto e toy arquanto folio e tute queste specie fay pestare insiema caxa como te piaxe, e se ne vo' fare piú, toy le cosse a questa medessima raxone et è meravigliosamente bona.
Translation by Helewyse de Birkestad, OL (Louise Smithson):
Sweet spices, enough for many good and fine thingsThe best fine sweet spices that you can make, for lamprey pie or for other good fresh water fish that one makes in a pie, and for good broths and sauces. Take a quarter (of an ounce) of cloves, an ounce of good ginger, an ounce of soft (or sweet) cinnamon, and take a quantity (the same amount of?) Indian bay leaves (*) and grind all these spices together how you please. And if you don’t want to do more, take these things (spices) in the same ratio (without grinding) and they will be marvelously good.