a better gluten free coffee and walnut cake

Yesterday's test coffee and walnut cake turned out to be too sweet and a bit too greasy.  Today's version has less fat and sugar and more walnuts.  It produces a light cake that is perhaps too walnutty for some, I just finished the packet so I let that urge overwhelm my first instincts on proportions.  Just reduce the walnuts if you want to, you don't need to change anything else.

This made two 8inch/20cm cakes.  I made a tiny test cake in a ramekin and it came out of the dish without any trouble, but if this is for a special event I recommend lining the tins with baking parchment.

250g flour (40%urid, 40% tapioca, 20% cornmeal)
5tsp baking powder (cut this down if you want a denser cake)
200 g butter, soft
200g sugar
2 tbsp instant coffee, dissolved in
2 dstp water
1 tbsp vegetable oil ( I find this helps keep a cake moist)
130g walnuts, finely chopped or whizzed in a blender (use 100g for a less intense flavour)
6 medium eggs

Beat sugar and fat together until light and creamy.  Add oil and eggs and beat.  Whisk flours and baking powder together, add chopped/ground walnuts and add to mixture.  Add coffee.  As this is a gluten free mixture you don't need to worry about over beating.

Spoon into prepared tins, level and bake at 170C (fan) for 30 minutes.  Turn out on to cooling rack.  Ice as desired when cold.

I will ice this with a thin layer of coffee butter cream in the middle and a glace icing on top for contrast.