Preheat oven to 200 degrees C and grease a loaf tin. Heat the rum and dates in a small saucepan just to the boil, then let cool and strain, reserved dates and liquid.
With a mixer, cream the butter and both sugars until fluffy, about 3 minutes. Add eggs one at a time while beating. Sift together the flour, cinnamon, cloves, bicarb soda, nutmeg and salt then add to the batter alternately with the apple sauce, beating until just combined. Fold in dates and walnuts.
Pour batter into loaf tin, cover with foil and bake 25 minutes. Remove foil and bake 20 minutes more. Let cool in the tin.
Make a glaze by combining the reserved rum with the honey and 50g butter in a saucepan. Bring to the boil then drizzle over the still warm cake.