For the cake: Preheat the oven to 350 degrees F. Cream the butter and sugar together until fluffy. Add the yolks in two additions, scraping well with a rubber spatula after each. Sift together the flour, baking powder and salt in a separate bowl. Mix in the dry ingredients in 3 additions, alternating with 2 additions of the milk and vanilla, waiting until everything is incorporated before each and scraping down the bowl.
Scrape the batter onto a jelly-roll pan lined with parchment paper. Spread with a spatula until very even. Bake for 17 to 18 minutes. When it has cooled to room temperature, refrigerate until cold.
For the cream: Meanwhile, whip together the cream, mascarpone and sugar until it reaches the consistency of sour cream. Do not over-whip; it will thicken up as it sits.
For the basil syrup: Blanch the basil in boiling water for 15 seconds, then immediately shock in ice water. Puree the leaves in a blender with the simple syrup and corn syrup until very smooth. Strain if necessary.
For assembly: Cut the cake into desired size, such as 3- to 4-inch circles or squares. Carefully slice in half horizontally. Put bottom halves on a plate, add basil syrup, a layer of strawberries, a scoop of mascarpone cream, more strawberries, basil syrup and top with the remaining cake halves.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.