Heat oven to 180C/160C fan/gas 4. Grease and line two x 23cm tins with baking parchment. Beat the butter, sugar and vanilla in a tabletop mixer (or with a hand mixer or wooden spoon) until the mixture is very light, pale and fluffy.
Gradually mix in the beaten eggs, scraping down the side of the bowl after each addition, until fully combined. If using a mixer, on slow, add the flour until just combined - don't over-beat as it can make the sponge heavy. If you're not using a mixer, fold in the flour with a large metal spoon.
Divide the mixture between the tins and bake in the oven for 30 mins or until the cakes come away from the side and the skewer inserted into the centre comes out clean. Remove and cool in the tin for 5 mins. Turn out onto a wire rack and remove the parchment to allow the steam to escape and the cakes to cool. Meanwhile, make the decorations.
Now assemble your cake. Before you split the sponges, trim the domed tops off each cake with a bread knife. Use the same knife or a cake wire, to split each sponge horizontally, so you're left with four sponge layers. A good tip is to cut a marker line on each sponge using a bread knife, so that once you've cut the sponges and filled them, you can use the line to put them back together in the right place. That way, if your cutting was a little wonky, it won't make the cake uneven.
Whip the double cream with the icing sugar and vanilla until light and fluffy, and just holding shape. Put the bottom layer on a cake stand or board. Spread with a thin layer of jam, then spread or pipe on a good layer of cream. Arrange an even layer of strawberries neatly round the edge, then dot the middle of the sponge with more fruit. Repeat with two more of the cake layers.
For the top layer, add the sponge and jam, but neatly pipe the cream over. Gently press gold leaf onto the chocolate on the strawberries, a few meringues and some of the bark.
Arrange the chocolate-coated strawberries on top of the creamy sponge, then nestle in shards of bark, meringues and biscuit. Finish with a sprinkling of crushed meringue and a little more of the freeze-dried strawberries (from the chocolate bark recipe). Serve and eat within a few hours.