Preheat the oven to 160 degrees Celsius. Line a 2lb loaf tin with baking parchment or a loaf tin liner.
Put 100g of the honey and 100g of the caster sugar in a large bowl. Add the butter and beat until well combined.
Add the eggs, 1 at a time, beating after each one.
Add the juice of 1/2 an orange and the zest of 1 orange to the bowl. Stir, then add the flour. Fold until it is all mixed in.
Spoon the batter into the loaf tin. Transfer to the oven and bake for 45 minutes to 1 hour, until a skewer inserted into the centre comes out clean. Remove from the oven.
Meanwhile, make the candied orange slices. Thinly slice half an orange, then cut those slices in half again. Put the water, juice of half an orange, 50 grams of honey and 50 grams of caster sugar into a saucepan. Bring to a simmer, add the orange slices then cook on a low heat for 30-40 minutes, until soft.
When you have removed the cake from the oven, place the orange slices on top to cover the whole cake. Pierce the cake in a few places with a skewer and drizzle over the syrup from the saucepan. Leave to cool fully before eating.