Preheat the oven to 190°C and grease and line a 20cm square cake tin.
Beat butter and sugar until light, then gradually add eggs and fold in flour and milk.
Bake the batter for 35–40 minutes until golden and a skewer comes out clean.
Cool the cake for five minutes in the tin before turning upside down onto a wire rack to cool completely.
Simmer sugar and water in a saucepan until dissolved and stir in the lemon essence.
Cream butter and icing sugar together until the filling is fluffy.
Remove the crust and slice the cooled cake in half horizontally.
Brush the bottom layer with syrup, spread with buttercream and jam, then replace the top layer.
Wrap the cake in cling film and chill for 2–3 hours to firm up.
Brush the top with apricot jam, apply rolled marzipan, and cut into 4cm squares.
Mix fondant icing sugar with hot water to create a thick coating icing.
Tint batches of icing with green, pink, and yellow food coloring.
Coat each cake square with icing and let them set on a cooling rack.
Pipe remaining icing and attach sugar flowers to decorate the cakes.