Decorating a Simple Buttercream Celebration Cake

Choosing Your Cake and Getting the Kit Ready

A celebration cake needn't be complicated. Two well-baked 20cm sandwich layers, a bowl of silky buttercream and a handful of flowers from the garden will give you something lovelier than anything shop-bought. The trick lies in the preparation, the temperature of your ingredients, and the patience to chill between stages.

Bake your sponges a day ahead if you can. Wrap them tightly in cling film once cool and leave them at room temperature overnight — they firm up slightly and become far easier to trim and stack. A cooler sponge also sheds fewer crumbs once you start to ice it.

For kit, you'll want:

• Two 20cm round tins, lined with greaseproof paper
• A wire rack, a long serrated knife and a cake turntable
• A palette knife and a flexible side scraper
• Piping bags with a large star nozzle and a small plain round one
• A cake board a few centimetres wider than the cake

Making a Buttercream You Can Rely On

The most stable choice is a simple American-style buttercream. Beat 250g of really soft unsalted butter on its own for a full five minutes until it pales and turns almost mousse-like. Sift in 500g of icing sugar in three additions, beating slowly at first so you don't shower the kitchen, then add a teaspoon of vanilla extract and a tablespoon or two of milk or double cream.

Consistency matters more than any recipe. You want a buttercream that holds a peak but spreads without dragging: firm enough to pipe, soft enough to glide. If it looks curdled, it's almost certainly too cold — set the bowl over a pan of barely simmering water for a minute and beat again. If it's sloppy, chill it for fifteen minutes and re-beat. Colour it pale pink with a dot of gel paste, never liquid colouring, which will loosen the mix.

Filling and Stacking

Trim the domed tops from both sponges with the serrated knife so they sit flat. If you like, split each layer horizontally to make four thin layers instead of two — more layers means more filling and a better ratio of cake to buttercream.

Anchor the base layer to the board with a smear of buttercream, then add roughly 150g to the centre and spread it outwards with the palette knife, leaving a 2cm border. Pipe a ring of firmer buttercream around the outside edge to act as a dam — this is what stops your jam or lemon curd seeping out. Add three or four tablespoons of filling inside the dam, top with the next sponge and press down gently. Repeat, then check the stack is level by crouching down and looking at it from the side.

The Crumb Coat: The Step Everyone Skips

The crumb coat is a thin, deliberately messy layer of buttercream that traps stray crumbs so they cannot ruin the final coat. Spread a scant layer over the top and sides, working from the middle upwards. Scrape off any excess, then chill the whole cake for at least 30 minutes — an hour is better, or 20 minutes in the freezer if you're short of time.

This chilling isn't optional. Cold buttercream is stable buttercream, and the firmer the crumb coat, the easier the final sweep.

A Smooth Final Finish

Pile the remaining buttercream on top and spread it over the sides, then hold your scraper at a slight angle against the cake and turn the turntable steadily. Scrape what comes off into the bowl rather than back onto the cake, as it will drag. Work in one direction, wipe the scraper clean between passes, and accept that you'll go round half a dozen times before it looks neat. For a sharp top edge, run a warm palette knife from the outside inwards. Chill again for 20 minutes before decorating.

Simple Piping and Fresh Flowers

Restraint is what makes a buttercream cake look professional. Choose one or two motifs and repeat them. A shell border piped around the base with a large star nozzle, using steady, even pressure, hides any unevenness at the bottom edge and frames the cake beautifully. A ring of small rosettes on top adds interest without fuss.

Fresh flowers should be the star. Cut them shortly before you need them and press the stems into a tiny offcut of sponge pushed into the top of the cake, so no stem touches the buttercream. Good choices include roses, ranunculus, spray carnations, gypsophila and, in summer, lavender and cornflowers. Avoid anything toxic — foxgloves, lily of the valley, hydrangea and daffodils are all best kept in the vase.

Finish with a light dusting of icing sugar, or nothing at all. Serve at room temperature: take the cake out of the fridge a good hour before cutting, so the buttercream softens and the sponge tastes of butter rather than cold.