In a mixing bowl, blend together ground almonds, icing sugar, corn syrup, and almond extract to make the marzipan mixture.
Divide the marzipan into three portions - one for the center of the cake (to be rolled into a 9-inch circle) and two for the topping.
Cream together butter and sugar in a mixing bowl until light and fluffy.
Gradually add eggs, flour, baking powder, mixed spice, and vanilla extract to the creamed mixture.
Fold in dried fruits such as sultanas, currants, raisins, and candied peel into the batter.
Preheat your oven to the specified temperature and prepare a cake tin.
Pour the cake batter into the tin, placing the circular marzipan layer in the center of the batter.
Bake the cake in the preheated oven until golden brown and a skewer inserted comes out clean.
After the cake has cooled, roll the remaining marzipan into 11 small balls and place them on top of the cake to represent the 11 faithful apostles.
Your Simnel Cake is now ready to be enjoyed as a traditional Easter treat!