This pretty cake is a show stopping dessert to impress guests.
Preheat the oven to 350 °F (180 °C). Grease 2 loaf pans that have a base measurement about 8-x-4-inches (20-x-10-cm) – a little larger or smaller will work fine. Line the pan with parchment paper.
Place the flour, sugar, ground almonds, baking powder and salt in a large mixing bowl or in the bowl of a stand mixer fitted with the paddle attachment. Add the butter and mix in until the mixture is a rough crumbly texture. Whisk the eggs, milk and vanilla together and add all at once to the bowl. Mix first on low speed then increase the speed to medium-high, beating for 2 minutes. Divide the batter in half*, scraping and spreading half of it into one prepared loaf pan. Add a little pink food colouring to the remaining batter, stirring well and then spread this in the other pan. Bake the cake(s) for about 30 minutes, until a tester inserted in the centre of the cake comes out clean. Cool the cake in the pan.
To assemble, trim away the outside edges of each cake. Slice each cake into 4 long strips. Trim each strip so that it is square and the brown bottom is trimmed away.
Stir the chilled, strained apricot jam to soften it and spread a thin layer over a strip of the pink cake. Top with a strip of yellow cake and repeat this with a second pink & yellow piece. Spread jam on one side of this duo and adhere the other duo, but inverted, so that no two like colours are touching (checkerboard). Repeat this with the remaining 2 pink and yellow cake strips, making two cakes.
On a surface lightly dusted with icing sugar, roll out half of the marzipan into a 9-inch (23 cm) square just shy of ¼-inch (6 mm) thick. Spread jam on one long side of the checkerboard cake and lay it, jam side down at one end of the marzipan. Trim the outside edges to the length of the cake. Spread apricot jam on the remaining 3 sides of the cake and roll it up with the marzipan, trimming where the seams meet. Use a pastry crimper or the back of a knife to mark patterns in the cake as you wish. Repeat this with the remaining cake
To serve, slice the cake into ½-inch slices. The cake will keep, well-wrapped (no need to refrigerate) for up to 5 days.