Make sure to preheat your oven to 350 degrees, and level your rack so that it sits in center position.
Butter two 9-inch round cake pans and then line with parchment cut to fit exactly—we don’t want any misshapen sides. Presentation is everything with this cake. Then butter your parchment and dust it with flour, tapping out the excess.
Whisk together your flour, baking powder, baking soda, and 1 teaspoon salt.
Beat butter and granulated sugar with a mixer on medium-high speed until pale and fluffy, scraping down sides of bowl as needed, for about 2 minutes. When this is done, reduce your speed to medium, and then add your eggs 1 at a time, making sure to beat them in well each time.
Beat in part of your flour mixture, alternating with buttermilk, but make sure you begin and end with the flour. Then add the vanilla until everything is combined.
Divide the batter evenly between pans—be careful here as you want your sponges to come out at exactly the same height.
Place them in the oven, wishing them well, of course, and then rotate the tins halfway through, until tops spring back when gently touched and a cake tester inserted into centers comes out clean. This should take about 40 minutes, but keep on an eye on it, especially for the last five minutes of baking.
Transfer your tins to wire racks, and let sponges cool in their tins for 20 minutes.
Meanwhile, make the macerated strawberries by combining them with the remaining 1/4 cup sugar, plus more if needed, depending on how sweet your strawberries are already, or how sweet your tooth is! Stir occasionally and leave them for at least 20 minutes and up to an hour if you have the time.
Once the cakes are cooled, run a knife around their edges, turn them out onto separate plates and make sure they have time to cool down completely.
While the cakes are cooling, get your basil cream infusion, and using a mixer, whisk the basil cream with the confectioners’ sugar in the chilled bowl on a high speed until soft peaks form.
Very, very gently add the macerated strawberries, making sure you keep back a handful of berries and all of the juices to drizzle over the top of the cake. Add a few more small (or torn) basil leaves to the cream.
Now layer each sponge cake with the basil mix.
Use the remainder of the basil cream to spoon over the top of the cake and pile the macerated strawberries on top.