Preheat oven to 160 degC fan
Grease and line the Battenberg tin with baking parchment
Beat the sugar and butter together
Whisk in the eggs and almond extract
Sieve and fold in the flour, baking powder and ground almonds
Half the mixture into two bowls
Add red food colouring to one of the bowls and fold in
Spoon the mixture into the tin so that 2 of the sections have the pink mixture and the other 2 have the non-coloured mixture, and level
Place in oven and bake for 25 mins or until cooked
Leave to cool for a bit; then remove from tin to completely cool on a wire racks
Roll out the marzipan big enough to wrap around the cake (tip: use two sheets of cling film, one above and one below, to stop sticking, then remove the top sheet before the next step)
Heat the apricot jam until runny
Cover the marzipan with some of the apricot jam
Brush apricot jam between a pink and non-coloured cake section and place in the middle of the marzipan
Assemble the remaining sections on top, brushing with the apricot jam, to make a chequerboard pattern
Warp the marzipan around the cake (if you used the cling film, you can use this to help keep everything tight).
Trim off excess marzipan and the ends of the Battenberg to neaten