can you taste the orange very much? i can't see how using marmalade would give a very strong orangey taste. this is the recipe incase you're not sure which cake i'm talking about:
125 grams of unsalted butter
100 grams of dark chocolate
300 grams of good quality orange marmalade
150 grams of sugar
a pinch of salt
2 large eggs
150 grams of self-rising flour
Melt the butter slowly in a heavy-bottom saucepan. When it's almost melted, add chocolate pieces, stir and take off the heat. Stir with a wooden spoon, until chocolate has melted.
Add the marmalade, sugar, salt and eggs. Stir thoroughly (it's okay to leave small visible chunks of marmalade in the batter).
Add sifted flour, stir and pour into a buttered and floured 20-22 cm loose bottomed cake tin.
Bake at 180ËšC oven for 45-50 minutes, until the cake has set (test with a knife or wooden stick).
Leave to cool in the tin for about 10 minutes, then slide onto a plate.