Baked Lumbarde Custard

I tried this recipe last year. I have had a few attempts at it. The taste is good, but the texture needs tweaking. My family (who generally don't eat medieval food) enjoyed it. I will keep working on it and post my final recipe when I am happy with it.

Custard lumbarde Recipe from A Boke of Kokery (Book of Cookery) c 1440
from: http://www.bl.uk/learning/timeline/item126388.html

Take good creme, and leuys of Percely, and yolkes and white of egges, and breke hem thereto, and streyne hem all þorg a straynour till hit be so thik that it woll bere him self. And take faire Mary and Dates, cutte in ij. or iij. and prunes, and put hem in faire coffyns of paast. And then put þe coffyn in an oven, And lete hem bake till thei be hard. And then drawe hem oute and putte the licoure into þe coffyns. And put hem into þe oven ayen. And lete hem bake til they be ynogh, but cast sugur and salt into þi licour whan ye putte hit into þe coffyns. And if hit be in lenton, take creme of Almondes and leve the egges. And the Mary.

 In present day English: Take good cream, and mix in leaves of parsley. Break the yolks and whites of eggs into the mixture. Strain through a strainer, till it is so stiff that it will bear (support) itself. Then take good marrow, and dates cut in 2 or 3 pieces, and prunes, and put them in nice coffins (pastry cases). Put the pies in the oven, and let them bake until they are hard. Then take them out and put the liquid into them, and put them back in the oven. Let them bake together until done, but add sugar and salt to the liquid when you put it into the coffins. And if it is in Lent, take cream of almonds and leave out the egg and the marrow.