Skip to content

How to decorate a faultline Christmas cake

Wow your guests with this stunning on-trend Christmas cake that's surprisingly easy to make. Take a clever shortcut with shop-bought fruitcakes to save time and learn how to create a sparkly faultline with our simple-to-follow tips and tricks. Don't forget to screenshot the handy ingredients list at the bottom ready for your next trip to store.

  1. Assemble the cake

    Using an electric hand whisk, beat 200g softened butter until light and creamy. Beat in 150g cubed Trex and 1½ tbsp sherry (or water). Gradually whisk in 700g icing sugar until smooth and spreadable, adding another ½ tbsp sherry (or water) if necessary. Transfer 300g to a second bowl and stir through 75g chopped walnuts. Halve one 800g fruitcake horizontally. Spread the top of the base with ⅓ of the walnut buttercream, then add the other half, cut-side up. Spread the top with another ⅓ of the walnut buttercream. Halve the second 800g fruitcake and place the top half on top, cut-side up, to create a third layer. Spread with the remaining walnut buttercream, then add the base, cut-side down. Using the flat side of a base piece of fruitcake for the top gives a nice smooth surface – perfect for adding decorations.

    Assemble the cake
  2. Smooth the icing

    Using a cutlery knife, evenly cover the cake with 250g of the plain buttercream, spreading to fill any gaps. Smooth the top and sides with a palette knife. Scrape any excess icing into a bowl and discard (as it may have crumbs in it). Wipe the palette knife with a clean, damp cloth, then gently smooth the cake for a really even surface. Chill for 45 mins.

    Smooth the icing
  3. Create a wide band

    Use a cutlery knife to spread a band of 150g salted caramel frosting around the middle of the cake, leaving about 3cm clear at the top and bottom of the cake. The band should be wider than you think – the buttercream will overlap it. Don’t worry if it isn’t neat: it will be covered in sprinkles. Mix 15g bronze crunch cake sprinkles, 50g gold crunch cake sprinkles, 20g white chocolate stars and 25g honeycomb pieces together in a small bowl.

    Create a wide band
  4. Add the sprinkles

    Put the cake (on its plate or board) on a baking tray. Gently press most of the sprinkles onto the caramel frosting to cover, reserving a few for the top of the cake. Keep regathering the bronze and gold sprinkles and pressing them onto the frosting until the faultline is completely covered. Brush off any sprinkles that may have stuck above and below the faultline. Remove the cake from the baking tray and chill for 30 mins.

    Add the sprinkles
  5. Make the faultline

    Add the remaining buttercream generously around the base and top with a palatte knife, ensuring it overlaps the sprinkles. Don’t smooth it too much, to maintain the 3D-layer effect. It doesn’t need to be too neat, just make sure it is a few millimetres thicker than the faultline and overlaps a little. Smooth with the palette knife. You will have ridges around the top edge: with the palette knife, draw these inwards for a neat edge. Chill for 4 hrs.

    Make the faultline
  6. Paint the line

    Mix ¼ tsp edible gold glitter with a drop of sherry (or water) to create a gold paint. With a thin paintbrush, paint the edge of the faultline. For a neat finish, it’s best to paint and add detail on the buttercream when it’s cold and firm – try to work as quickly as possible. Brush 12 meringue shells with extra glitter, then place around the top edge of the cake.

    Paint the line
  7. Serve

    Scatter the reserved sprinkles on top and serve. The cake will keep, covered, for up to 5 days.

  8. Ingredients

    We've made a handy shopping list so you can get everything you need to make this Christmas show-stopper. Don't forget to screenshot before you go shopping!

    200g butter, softened
    150g Trex, cubed
    1½ tbsp sherry (or water), plus a drop extra
    700g icing sugar
    75g walnut halves, chopped
    2 x 800g rich fruitcakes
    150g salted caramel or chocolate
    flavour frosting
    15g bronze crunch cake sprinkles
    50g gold crunch cake sprinkles
    20g white chocolate stars
    25g honeycomb pieces
    ¼ tsp edible gold glitter, plus extra
    for the meringues
    ½ pack Tesco Finest 12 Meringue Shells

    Serves 24

    Each serving contains

    • Energy

    • Fat

      23g 33%
    • Saturates

      11g 53%
    • Sugars

      70g 78%
    • Salt

      0.3g 5%

    of the reference intake
    Carbohydrate 83.8g Protein 3.1g Fibre 2.1g