Preheat oven to 350°F/177°C. Line 2 round 6" pans with parchment paper.
Combine the cream and vanilla extract in a bowl, give it a stir and set aside.
Add eggs to a mixer bowl over a double boiler filled with hot water.
Bring the water to a simmer and begin whisking the eggs until foamy.
Add in granulated sugar and continue to whip until it reaches 30C. Mixture should be warm.
Continue to whip until the eggs are light and fluffy, about tripled in volume, at least 5-7 minutes on high speed.
Sift in cake flour in two additions, folding it in with a spatula.
Take a little of the cake batter and mix it with the cream and vanilla mixture to lighten.
Pour the lightened cream mixture into the cake batter and gently fold it in, taking care not to deflate the entire mixture.
Divide the cake batter into two 6" round pans lined with parchment paper.
Give the pans a few taps to release any trapped air bubbles.
Bake at 350°F/177°C for 23-25 minutes, until golden in colour and a toothpick inserted comes out clean.
Remove from oven and cool cakes completely on a wire rack.
Use a sharp serrated knife to trim the tops off each cake, and slice each cake in half to create 4 layers.