Pour the superfine sugar into the mixer bowl with the eggs; whisk to combine.
Beat the mixture on medium high until it’s very light in color and triple in volume (this will take up to ten minutes with a stand mixer).
Add the vanilla; beat an additional 10-15 seconds.
Pour a cup or so of the egg mixture into the cooled melted browned butter; stir it until it’s completely incorporated, (this eases the incorporation of the butter into the batter).
Then gently pour into a wide shallow bowl.(this eases the incorporation of the flour.)
Sprinkle the flour mixture into the mixer bowl in thirds; carefully fold until the flour mixture and the butter mixture are completely incorporated.
Gently pour the batter into the prepared pan.
Bake until the cake is a pale gold color and springs back lightly when touched.
Notes
I used some of my strawberry freezer jam I warmed in the microwave. I painted the bottom of cake before I added the mascarpone cheese to keep the cake moist. I also used some to paint the berries to give them a gloss and maintain their moisture.
The mascarpone is loosened with a little whipping cream and sweetened with a little honey.
Recipe by Make Mine Lemon at https://www.makeminelemon.com/genoise-a-party-cake/