Preheat your oven to 350°F (175°C) and grease a specialized Battenberg tin or an 8-inch square pan divided down the middle with foil.

In a large mixing bowl, cream together the softened butter and granulated sugar until the mixture is pale and fluffy.

Beat in the eggs one at a time, adding a spoonful of flour with each egg to prevent curdling, then fold in the remaining flour, ground almonds, and baking powder.

Divide the batter evenly into two separate bowls; stir the lemon zest into one bowl to create the yellow sponge.

In the second bowl, add the raspberry extract and a few drops of red food coloring, mixing until you achieve a vibrant pink color.

Spoon the batters into the separate sections of your prepared tin, smooth the tops, and bake for 25-30 minutes until a skewer inserted into the center comes out clean.

Allow the cakes to cool in the tin for 10 minutes before transferring them to a wire rack to cool completely.

Trim the cooled cakes to ensure they are identical in size, then cut each sponge in half lengthwise to create four long rectangular strips.

Brush the long sides of the strips with warmed apricot jam and assemble them into a checkerboard pattern, placing one pink strip next to a yellow one for the bottom layer, and reversing the colors for the top layer.

Roll out the marzipan on a surface dusted with powdered sugar, brush the outside of the cake assembly with jam, wrap it tightly in the marzipan, and trim the ends for a neat finish before serving.