In a medium bowl, whisk together the cake flour, baking powder, and salt. Using a stand mixer fitted with the whisk batter, whip the cream, starting on low speed, gradually raising the speed to medium-high as it thickens, until stiff peaks form. In another bowl, whisk the eggs and vanilla until just combined.

On medium-high speed, gradually beat the egg mixture into the whipped cream. Gradually beat in the sugar. It should take about 30 seconds to incorporate it. Then add half the flour mixture into the cream and, with a large spatula, stir and fold in the flour until most of it disappears. Add the rest of the flour and continue folding and mixing until all traces of flour have disappeared. 

Scrape the batter into the prepared pan. Smooth the surface evenly. Bake the cake for about 30 to 35 minutes (I baked mine at 30), or until a wooden toothpick inserted comes out clean. Let the cake cool in the pan on a wire rack for 10 minutes. Invert the cake onto a wire rack to finish cooling. Lightly dust the cake with icing sugar, if desired.