Preheat the oven to 180°C.
Grease and line the bases of two 20cm round cake tins with parchment.
Whisk sugar, eggs, and olive oil for 4 minutes until smooth.
Sift in flour, mixed spice, and bicarbonate of soda and stir gently.
Fold in grated carrots, pecans, lemon zest, sultanas, raisins, and coconut.
Divide mixture between tins and bake for 35 to 40 minutes.
Cool cakes in tins for 5 minutes then transfer to a wire rack.
Beat icing ingredients until fluffy and chill for 1 to 2 hours.
Boil baby carrots with water, salt, sugar, and butter for 6 minutes until glazed.
Roll glazed carrots in extra caster sugar and allow to cool.
Spread icing between layers and on top once cakes are cold.
Decorate with extra pecans and the sugared carrots before serving.