From Libre del coch, 1520 English translation by Lady Brighid ni Chiarain.
Take almonds which are select, and wholesome, and well-peeled in boiling water. And grind them very well, moistening the pestle of the mortar in rosewater so that they don’t become oily. And when they are well-ground, cast in as much syrupy sugar as there will be almonds; and let it be well-ground, and strained through a silk sieve; and make good paste incorporating the sugar little by little, and not with large amounts, so that you don’t make the paste viscous, and spread them out very well.
The way to cook and glaze them:
Take fine sugar which is very well-ground, and strain it through a sieve of silk; and for a syrup put it in this way, and blend it with rosewater which is reasonably thick.
It is necessary that the oven is not very intense, but temperate; and take the sheet on which you will cook the marzipans, and heat it in the oven; and when it is hot, cast flour on it, under the marzipans, so that they don’t stick; and put them in the oven until you see that you cannot bear to touch them with the back of your hand; and if the outside is not cooked, be sure to return it to the edge of the sheet with the outside on the inside. And then take them out and with a little spoon cast glaze upon them, and with some feathers spread it out all over. And then return them gently to the oven until the glaze hardens, as you think [right] according to the practice you have seen.
My quick & easy recipe:
2 cup almond flour
1 c confectioner’s sugar
1 T rosewater
1-2 T cold water
1/4 c confectioner’s sugar
enough rosewater to form a glaze
Mix together almond flour and sugar. Add rosewater and enough water to form a dough. (You can add more sugar if it’s too sticky). Roll into 1″ balls and flatten slightly. Bake at 250 for 15 minutes. Brush with rosewater glaze and bake for an additional 45 minutes until just set. (Keep checking so they don’t over cook.)