Adapted from Nigella Lawson's How To Be A Domestic Goddess (and translated to American measurements)

Ingredients:
1.5 cubes unsalted butter
1.5 bars of 73% organic dark chocolate (trader joes or green & black worked well)
16 oz of good quality orange (or tangerine -- which I used) marmalade
1.5 cups of sugar (Nigella uses 2 cups - I used organic evaporated cane juice crystals)
1/2 T of salt
3 large eggs
1 2/3 cups of self-rising or pastry flour, well sifted before measurement

Melt butter slowly in a heavy-bottom saucepan. When it's almost melted, add chocolate pieces. Remove from heat. Stir with a wooden spoon, until chocolate has melted.

Add 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 / floured 10" springform cake tin.
Bake at 350˚F 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.

Dust with powered sugar through a sifter on the top.