Preheat oven to 300Ëš Fahrenheit. Line a large loaf pan (9.25"x5.25"x2.75") with parchment and set aside. Cover the dates and raisins with boiling water and set aside.
In a large heavy-bottomed saucepan, melt the butter and brown sugar over low heat, stirring occasionally. When the butter is totally melted, take the pan off the heat and leave to cool slightly (you don't want to cook the eggs). You can peel and chop your apple at this point if you haven't done so already.
With a wooden spoon, beat the eggs, one at a time, into the butter/sugar mixture. Stir in the lemon zest and the vanilla extract.
Beat in the flour, baking powder and salt. Make sure they are well-combined, but don't over mix.
Drain the dates and raisins. Peel the dates if they have a tough outer skin. Chop them up. Stir into the cake batter with the raisins, chopped apple and ginger.
Pour batter into prepared tin and bake, in the middle of the oven, for about 2 hours, or until a cake tester comes out clean. Check early to be sure not to bake too long. You want the cake to be moist. Cool the cake in its tin.