1. Measure out the sponge ingredients, separate the eggs and leave everything out to reach room temperature for about 20-30 minutes. (Cover the eggs to stop them from drying out).
2. Grease the cake tin with a thin layer of butter over the base and sides and line it with parchment paper.
3. Preheat the oven to 180°C (356°F) or 170°C Fan (338°F).
4. In a large clean and dry mixing bowl, add the egg whites and lemon juice. Mix using an electric mixer and whisk until foamy and doubled in size.
5. Add the caster sugar to the egg whites one third at a time making sure it's fully incorporated before adding the next third.
6. Continue to whisk until the meringue reaches stiff peaks. The meringue should be glossy and smooth with peaks that point up without folding over.
7. Add the egg yolks one at a time, whip using the electric mixer for about 10-15 seconds for each yolk and stop as soon as they're incorporated into the meringue.
8. Sift your flour twice into a separate bowl. On the third time, sift one third of it into the egg mixture and fold gently with a silicone spatula. Repeat until all of the flour is incorporated into the mixture, being careful not to over mix.
9. Mix the melted butter and milk in a small bowl. Add about 2 tbsp of the sponge batter and whisk them together to temper.
10. Pour the tempered mixture into the cake batter and fold in gently with the spatula.
11. Once combined, pour the mixture into the lined cake tin and smooth the top.
12. Drop the cake tin onto a hard surface from about 10cm (4 inches) high. Repeat once more and then place straight into the oven for 20-30 minutes. (Check the cake after 20 minutes and remove once it's golden brown. I personally take the cake out at 23-24 minutes.)
13. Once the sponge is fully cooked, take it out from the oven and drop it on a hard surface from about 20cm high (8 inches). This will shock the cake and stop it from shrinking.
14. Turn upside down onto a wire rack and remove the cake tin. (Be careful not to burn yourself.)
15. Leave to cool for about 1 hour.

Syrup

1. In a small pan, add the caster sugar, water and liqueur of your choice.
2. Bring to a boil over a medium heat while stirring continuously. 
3. Once it starts bubbling, stop stirring and allow to boil for 1 minute.
4. Remove from the heat.
5. Once the cake has cooled, cut off the top (as thinly as possible to not waste too much) and then cut through the middle horizontally. 
6. Brush the top of each half generously with syrup and save any leftovers for later.

Prepare the Strawberries

1. Wash the strawberries, dry them thoroughly with a paper towel and remove the stems.
2. Divide your strawberries so that the most beautiful ones will go on top. I recommend 7-9 for decorating the top. Place them on a plate lined with kitchen paper to absorb the excess moisture.
3. Slice the remaining strawberries for the filling.

Whipping Cream

1. Take a large bowl and add a few handfuls of ice, then take a smaller glass or steel bowl (preferably chilled) and place it on top of the ice.
2. Pour in the cream and add powdered sugar and a few drops of vanilla.
3. Use an electric whisk (or balloon whisk if you're whisking by hand) and whip until the cream has peaks and becomes spreadable.

Assembling

1. Place 2-3 spoonfuls of whipped cream in the centre of each half of the sponge. Spread it out to the edges until even.
2. Arrange the strawberries on one half and then flip the other half on top so that the cream and strawberries are sandwiched in the middle.
3. Brush any leftover syrup on the top of the cake and place it on a easy-to-turn surface (e.g. cake board, paper plate etc.)
4. Add about 4-5 scoops of whipped cream to the middle and spread it out thinly over the edges. This is a crumb coat (to smooth down crumbs) so scrape off any excess into a separate bowl so that crumbs don't mix in with the rest of the cream.
5. Whip up the cream a little bit more to make it a bit thicker and then add 3/4 of it to the top of the sponge and the other 1/4 to a piping bag. Place the piping bag in the fridge for a few minutes.
6. Spread out the cream using an icing spatula, making sure the whole cake is evenly covered on the top and sides.
7. Finish the cake by piping swirls around the edge and placing the strawberries in the center.
8. Decorate with mint leaves and any other Christmassy decorations you might have!
9. Enjoy!