Preheat the oven to 180C/350F and grease and line three 8 inch round cake tins. I spray them with Wilton Bake Easy and then line the base and sides with grease proof paper.
Place butter/margarine and sugar into a large bowl, or the bowl of your stand mixer, and beat until light and fluffy. 2-3 minutes on medium-high speed.
Add in the eggs and vanilla extract, scraping down the sides of the bowl as necessary, and mix on medium-high speed until well incorporated and smooth, around 1 minute.
Add in the flour, baking powder and salt, if using, and mix on low until the mixture starts to combine. Then add the milk and continue to mix on low-medium speed until everything is combined and smooth.
Divide the cake batter between the cake tins. I use a 1/2 cup measurements and place 1/2 cup of batter in each tin, then repeat until all the batter is in the tins.
Place in the oven for 20-25 minutes, until risen, lightly golden and a skewer into the centre comes out clean.
Leave to cool in the pans completely. At this stage you can wrap the cake layers in cling film and leave them overnight before decorating.
Once the cakes are cool; place double/heavy cream and icing sugar into a large bowl and whisk until soft peak. You want it to hold a peak when you pull the whisk out, but for the tip of the peak to bend over on itself. You need it to be easily spread over the cakes!
Place all but 5-6 of the meringue swirls into a medium sized bowl and crush. Either with your hands or a rolling pin.
To assemble: Place a small amount of cream into the centre of a plate/cake board and then place one cake layer onto the plate. For the first layer, I put them flat side down, so the base of the cake is flat and sticks to the plate.
Use a small angled spatula to spread a 1/4 inch layer of cream on the top of the cake.
Place half of the halved strawberries on top of the cream. I placed them around the edge with a 1/2 inch gap between them and then placed a few in the centre.
Sprinkle some of the crushed meringue in between the strawberries.
Take another cake layer and place a little cream on top of the cake; just a thin layer to help it stick to the layer beneath it. Flip the cake so the flat base faces upwards and then place it on top of the cake covered in strawberries. Press lightly to stick the cake to the strawberries below.
Spread another 1/4 inch thick layer of cream on to the second cake, then repeat the above steps with strawberries and meringue.
Take the final layer of cake and spread a thin layer of cream onto the top. Flip it so the flat base faces upwards and place it on top of the second layer and press lightly to adhere it.
At this stage, cut your straws to the height of the three cakes and push them through the cake. I placed mine a few inches in from the edge in a square shape. Just make sure they're fairly evenly spaced.
Place a 1/4-1/2 inch layer of cream onto the top layer of cake and spread into an even layer.
At this stage you can decorate the top how you like: I placed 1 strawberry in the centre and then placed 5 around it in a circle. Then in the gaps between the strawberries, I placed the meringue swirls around the edge of the cake. To finish it off I sprinkled some more crushed meringues over the top.
If there is any cream leaking over the edges, just wipe it away with a clean finger or a small spatula, it doesn't matter if you see cream around the edges of the cake; it adds to the look of this naked cake!
Eton Mess Cake will keep covered, in the fridge, for 2 days.