Preheat oven to 180°C and line an 18cm square tin.
Melt butter and whisk eggs and sugar until thick and pale.
Fold flours and cooled butter into the egg mixture in two batches.
Bake for 35 minutes and cool on a wire rack.
Melt butter with coffee powder and beat in icing sugar for the icing.
Boil sugar and 30ml water to form a slim thread syrup.
Whisk hot syrup into egg yolks until thick and cold.
Beat egg mixture into creamed butter and add coffee essence.
Slice cake horizontally, sandwich with coffee icing, and cut into 9 squares.
Brush cake sides with sieved apricot jam and press almonds on.
Pipe buttercream rosettes around the top and bottom edges of each cake.
Mix fondant with 60ml water and colouring, then glaze the cake centres.