Simnel Cake Calculator

The 11 balls represent the apostles, minus Judas. They are placed around the top edge of the cake before a brief browning under the grill or with a blowtorch. This is a tradition dating back centuries in British Easter baking.

Divide your marzipan into three portions: one third for the middle layer, one third for the top, and one third for the 11 balls. Roll the middle portion into a circle the same diameter as your tin, place half the cake batter in the tin, lay the marzipan disc on top, then add the remaining batter.

Bake at 160°C (140°C fan / Gas 3). Like all fruit cakes, a lower temperature prevents the outside from burning. Line the tin well with baking parchment. The marzipan layer in the middle will stay soft and gooey.

The bake time this calculator gives is an indicative guide scaled from Mary Berry's 1¾–2 hours for a 20cm round. Ovens vary, so test for doneness rather than relying on time alone: the cake should be golden-brown and firm in the middle, and a skewer pushed into the centre (away from the marzipan disc) should come out clean. If the top browns too quickly, cover it loosely with foil.

Cake batter scales by tin area, not diameter, because the depth stays the same. A round tin's area is π × (diameter ÷ 2)², while a square tin's area is the side length squared. A square tin therefore holds about 27% more than a round of the same nominal dimension, so a 20cm square needs noticeably more batter than a 20cm round. This calculator handles that for you when you pick the shape.

Yes, the un-decorated cake (without the top marzipan) keeps well wrapped in foil for 2-3 weeks. Add the top marzipan and decorations on the day or a few days before serving. It does not need as much maturing time as a Christmas cake.

Both are rich fruit cakes, but simnel cake is traditionally made for Easter and has a layer of marzipan baked into the middle and on top, decorated with 11 marzipan balls representing the apostles (minus Judas). Christmas cake is typically covered with marzipan and royal icing or fondant, and is made further in advance.