Included merely to show that it wasn’t overlooked, but there is little of a positive nature to explain the origin of the word marchpane, despite much discussion.
Similar forms appear in various of the languages of Europe, apparently all derived from Italian marzipani.
Some say that that was derived from the name of a Venetian coin, the matapanus, and was transferred to the confection purchasable by that coin.
Others say its source was the Latin Martius panis, “bread of Mars.”
The latter certainly bears greater plausibility.