I based this cake on the Hummingbird Bakery recipe with some scaling adjustments. I baked all the cakes in Invicta cake tins (heavy duty quality tins) and I would recommend them to anyone who wants to invest in cake tins to last them a lifetime.
Recipe for the Cake:
I made the cake up of 4 thin layers. The recipes below are the quantities required for each thin layer, so when shopping you will need 4 times the amount of ingredients shown. Ingredients listed in the order that you will need them.
90g unsalted butter, room temperature
225g caster sugar
1.5 large eggs (beat the second egg up but try and pour in only half - it's an art not a science!)
1/4 tsp of Red food colouring paste (I use sugarflair spectral colours and the results are brilliant every time, available in specialist cake shops and online)
3/4 tsp vanilla
225g plain flour (doesn't need to be sifted, the only thing I sift is icing sugar)
3/4 tsp salt
3/4 tsp bicarbonate of soda
2 1/4 tsp (12.5 ml) white wine vinegar
You can do this recipe with a wooden spoon, a hand mixer or a stand mixer. I've done it with both a hand mixer and a stand mixer and they both came out the same.
1/ mix together the butter and caster sugar. The hummingbird bakery book says mix until light and fluffy. Personally I think the ratio of sugar to butter is too high to get anything that resembles light and fluffy so I just mix until well combined.
2/ beat the eggs and add slowly to the mixture whilst mixing. Keep mixing until thoroughly combined.
3/ in a small separate bowl, weigh the cocoa, add the food colouring, water and vanilla essence. Mix together into a paste. It might take a while, I found the cocoa was a bit hydrophobic so it was determined not to combine for as long as it could. When the paste has come together, put it into your egg/sugar/butter mixture and mix until you get a nice consistent colour throughout the mixture.
4/ add half the buttermilk and keep on mixing until combined. Then add half the flour and mix until this has all been incorporated.
5/ repeat step 4 until all the buttermilk and flour have been added.
6/ add the salt, then the bicarbonate and then the white wine vinegar mixing all the time. Mix for a few more minutes for good luck.
7/ pour into your lined and prepared baking tin and bang the tin on the table a few times to level the mixture and get rid of any big air bubbles.
8/ bake in a preheated oven for 25 mins at 150 degrees C for fan assisted, otherwise at 170 degrees C. A skewer should come out clean when inserted the full depth of the cake. I find an oven thermometer helpful to really be sure of your temperatures - they only cost a few pounds from somewhere like TKMaxx and can save a cake disaster from happening!
9/ remove from the tin and leave to cool on a wire rack, you can leave the lining paper on to prevent the cake from drying out. I found the best way to get it out of the tin was to grab the lining paper on opposite sides of the cake and lift it quickly and smoothly out of the tin. The cake will bend in the middle, but its not detrimental. It might crack a wee bit, but let's face it, it's going to be slathered in frosting anyway so no-one is ever going to know :)
I've raided my photo album on my phone to disappointingly find I have no pictures of the cake at this stage. I've got one of a small sample cake I did with frosting on it but the sides are open so you can clearly see the nice red colour. It's a colour that you just won't get with liquid food colourings, and the natural food colourings you will find turns the cake brown instead of glorious red. If you can get hold of sugarflair colours you won't go wrong.