a Bride Cake en-robed in icing would last for a long time. Months if not years....It might get a little dry but the addition of a little brandy would alleviate that problem ;-)

Elizabeth Raffald’s recipe book The Experienced English Housekeeper(1769), was the first book in the English cooking tradition to give a recipe for an iced bride cake, and the recipe is one that has survived at traditional English weddings today. (Slightly off topic it was not unknown in the late 19th century/early to mid 20th century for the top layer of a wedding cake to be kept uncut to serve as the Christening cake for the first child of the union.its keeping qualities are noted ;-).... )

Do note that in addition to the fruitcake base Mrs Raffald give recipes for Almond Icing( marzipan) and Sugar Icing( royal icing), which are to be placed on top of the cooked cake. This helps preserve it .

Here is Elizabeth Raffald's classic Bride Cake recipe:

To make a Bride Cake

Take four pounds of fine flour well dried , four pounds of fresh butter, two pounds of loaf sugar , pound and sift fine a quarter of an ounce of mace, the same of nutmegs. To every pound of flour put eight eggs.(32 eggs by my reckoning-JW)Wash four pounds of currants, pick them well and dry them before the fire .Blanch a pound of sweet almonds( and cut them lengthways very thin) a pound of citron, one pound of candied orange , the same of candied lemon, half a pint of brandy.

First work the butter with you hand to a cream, then beat in your sugar a quarter of an hour.

Beat the whites of your eggs to a very strong froth, mix them with your sugar and butter, beat your yolks half an hour at least and mix them with your cake.

Then put in your flour, mace and nutmeg ,keep beating it well till your oven is ready, put in your brandy and beat your currants and almonds lightly in.

Tie three sheets of paper round the bottom of your hoop to keep it from running out, rub it well with butter , put in your cake, and lay your sweetmeats in three lays with cake betwixt every lay.

After it is risen and coloured, cover it with paper before your oven is stopped up .It will take three hours baking.