Gluten-free Carrot Cake

I am forever looking for new recipes to expand my repertoire of gluten-free recipes. Last Sunday we hosted a BBQ in our garden, which later turned into a summerhouse dinner thanks to the fickleness of the English weather. One of our guests is a coeliac, and each time he's coming, I try to bake something new for him, so he's my perfect gluten-free guinea pig (sorry, Jay!). As we all enjoy cakes, I decided to bake a Carrot Cake. My recipe is an adaptation of Phil Vickery's version from Seriously Good Guten-Free Baking.

Gluten-free Carrot Cake
Ingredients:
3 eggs
150g light brown muscovado sugar
125ml mild olive oil
225g gluten-free flour (I use Doves Farm brand, which is very good)
1tsp baking powder, gluten-free
1tsp xanthan gum (optional)
1tbsp Vandotsch Speculaas spice (or use a mix of ground cinnamon and ginger)
200g grated carrots
50g chopped walnuts
zest of 1 orange
3tbsp orange juice

for the frosting:
4tbsp icing sugar
1tbsp+ orange juice
250g quark
orange zest+sugar for decorating

Beat the eggs with sugar, add the olive oil and mix well. I like to use milder varieties of olive oil in a carrot cake as the extra virgin variety could be overpowering in a dessert. Add the gluten-free flour, baking powder, xantham gum (which is added for texture rather than flavour), spices, mix. Grate the carrots and chop the walnuts, and add both to the cake mix. Finely zest one orange and add to the batter. It is quite dense, so you might want to loosen it up a bit by adding some orange juice or milk.
Spoon the mixture into a cake tin, and put the tin in the oven preheated to 180C. Bake for about 45 minutes, check with a wooden skewer if the cake is ready.
Cool in the tin for ten minutes, then turn it out onto a plate. Once completely cool, slice the cake into two circles, using a big thin knife.
Prepare the frosting by mixing the icing sugar with the orange juice, it should be smooth but not too runny. Add the quark and mix well. Divide the frosting in two and spread on the both layers. Place one layer on top of the other.
In a small pan dissolve 1 heaped tsbp of sugar with some orange juice and add the grated orange zest. Cook for a few minutes. Once it's cooled, decorate the top frosted layer with the orange bits.

I recently received a small packet of Vandotsch Speculaas spice, which is a mix of nine spices including high grade cinnamon, cloves, ginger and others. It is very aromatic and all the flavours are beautifully balanced. This spice is created, using a family recipe.

You can substitute it with 1/2tsp of cinnamon and 1/2 ground ginger.

It was a tasty cake, though the texture was different from a "normal" carrot cake, it was not as crumbly-fluffy.