Traditional Battenberg Cake - unsalted butter

Method

• Preheat oven to moderate 350°F. Grease an 8"/20cm square baking tin with butter. Line the tin with parchment paper, creating a divide in the middle with the parchment (or foil).
• In a stand mixer fitted with a paddle attachment, cream butter and sugar until creamy. Add the eggs one by one and beat until pale yellow; add the extract. Mix all the dry ingredients together. Now add it to the above mixture. Beat on medium speed until mixed. Spoon half the mixture into the one side of the prepared baking tin. Add a few drops of the food color to the remaining batter, stir until the color is thoroughly distributed, add more color if needed.
• Spoon the pink batter into the other half of the prepared baking tin. Smooth the surface of the batter with a spatula, making sure batter is in each corner
• Bake for 25-30mins until the cake is well risen, springs back when lightly touched and a toothpick comes out clean (it should shrink away from the sides of the pan). Leave to cool in the tin for a few minutes before turning out to cool thoroughly on a wire rack.
• Once completely cool, trim the edges of the cake with a long serrated knife. Cut each colored sponge in half length ways so that you are left with four long strips of sponge. Neaten the strips and trim as necessary so that your checkered pattern is as neat and even as possible. Gently heat the apricot jam and pass through a small sieve. Brush warmed jam onto the strips of cake to stick the cake together in a checkered pattern (one yellow next to one pink. On top of that, one pink next to one yellow). Dust a large flat surface with icing sugar then roll the marzipan in an oblong shape that is wide enough to cover the length of the cake and long enough to completely wrap the cake. Brush the top of the cake with apricot jam. Place the cake on the marzipan, jam side down