Preheat the oven to 180ºC and grease the inner side and base of a medium spring-form tin. Line the base with parchment paper.
Zest one orange, then juice it. Juice the other orange too. Scoop out any reaming flesh and cut this into small bits.
Put the raisins in the juice and set aside.
Grate the carrots.
In a mixing bowl, whisk together the eggs and sugar, then add the oil and honey. Combine, then add spices and mix again.
Stir in the carrots, orange zest & flesh and the raisins with the juice.
Sift the flour & baking powder into the mixture and fold gently until just combined.
Add the chopped hazelnuts and fold through.
Tip the mixture into the prepared cake tin, then bake for 25–30 minutes in the middle of the oven.
When an inserted skewer comes out clean and the top of the cake is golden, remove the cake from oven and rest for 5 minutes.
Transfer the cake to a wire rack and let it cool completely.
Whilst the cake is cooling, you can make icing using more blood oranges, or frosting with cream cheese or just decorate it with caramelised orange rings/segments.