Making the sponges:

Step 1

Melt the butter, and mix with the sugar and eggs.

Step 2

Add the flour, and vanilla until fully incorporated and divide equally between 3 bowls.

Step 3

To one bowl add the red, and to another add the blue food colouring, mixing thoroughly.

Step 4

Transfer the mixtures to 3 lined and greased 6 inch cake tins and bake at 180°C for 35 minutes.

Step 5

Leave to cool in the tins for 10 minutes then transfer to a wired rack and leave to cool fully.

Meanwhile make the buttercream:

Step 6

Heat the egg whites and sugar over a pan of simmering water until the sugar has fully dissolved (check there’s no graininess between your fingers).

Step 7

Whisk until stiff peaks form then add the butter and beat on high until it forms a thick buttercream.

Step 8

Turn the mixer onto low and mix (preferably with a paddle not a whisk at this point) until it goes silky smooth.

Step 9

Level the cake sponges, and then stack with a layer of buttercream and jam.

Step 10

Use the buttercream to crumb coat the cake, smoothing with a scraper, and then chill in the fridge for half an hour.

Step 11

Cover the cake in the buttercream, again using a scraper until it is smooth.

Adding final decorations:

Step 12

Colour the remaining buttercream red and blue, leaving some white and with a range of piping tips, transfer to piping bags and create your design!

Step 13

Use a mixture of open and closed star nozzles of different sizes to create the range of effects.

Step 14

For the crowns, use the Renshaw sugar paste to press into a silicone crown mould, and carefully remove.

Step 15

Use the Rainbow Dust silver lustre dust and sparkle spray to create the platinum crowns, and then press lightly onto the cake!

Step 16

Give the cake a final spritz with the sparkle spray and there you have it, a cake fit for the Queen’s Platinum Jubilee!