Step 1

Pre-heat your oven to 160ºC/140ºC fan.Line two 20cm round sandwich tins with greaseproof paper or re-usable baking tin liners (I use these tins and these liners).

Step 2

Put all of the cake ingredients into a large bowl (3 tbsp coffee powder, 200g plain flour, 2½ tsp baking powder, 220g soft light brown sugar, 220g margarine or butter, 4 medium eggs, 2 tsp milk, ⅛ tsp salt). Beat with an electric mixer or by hand on a low speed until all of the ingredients are combined.

Step 3

Split the mixture between the two prepared tins. Then bake for 30-35 minutes until a skewer inserted in the centre comes out clean.

Step 4

Once the cakes are cooked, remove them from the oven. Leave them to cool in their tins for about 10 minutes before removing them from the tins and moving them to a wire rack to cool completely.

Step 5

While the cakes are cooling make the coffee buttercream. Start by mixing together the instant coffee powder/granules (8 tsp) with the boiling water (4 tsp). Set aside to cool.

Step 6

In a large bowl beat the butter (200g) and vanilla extract (¼ tsp) on a low speed until soft. Add the icing sugar (400g) and beat on a low speed until combined with the butter and smooth. Gradually add the coffee mixture, 1 tsp at a time. After each addition beat the buttercream until the coffee has been fully combined before adding more.

Step 7

Check the consistency of your buttercream. It should be soft enough that you could spread it onto a slice of bread. If it is too firm, then add a little milk (no more than 1 tsp at a time) until it is your desired consistency.

Step 8

Place the bottom layer of your coffee sponge onto your serving dish. Spread about ⅓ of the coffee buttercream evenly across the sponge (I like to use a palette knife, but you could use a regular knife or the back of a spoon).

Step 9

Add the top layer of sponge. Again spread ⅓ of the coffee buttercream on top. Put the remaining buttercream into a piping bag fitted with a large star nozzle (I use a JEM1B nozzle). Pipe 12 blobs of buttercream evenly spaced around the edge of the cake. I give the piping bag a little wiggle as I squeeze so that the buttercream looks slightly ruffled.Of course, if you don't fancy piping, simply split the buttercream even between the middle and top of the cake.

Step 10

Serve