Preheat your oven to 325°F.
Thoroughly spray a 10-cup Bundt pan with nonstick spray.
Sprinkle in about ½ cup all purpose flour and rotate the pan to coat the interior with the flour. Make sure to get the flour up the sides of the pan as well as up the central tube. Turn the pan upside down and firmly knock out the excess flour. Set aside.
Whisk together the cake flour, salt and baking powder. Set aside.
In the bowl of your stand mixer, beat the butter on medium speed until smooth and soft, scraping bowl as necessary.
Add the sugars and cream on medium-high speed until very light and fluffy 5-7 minutes. Scrape the bowl.
Add the eggs, one at a time, beating them in--first on low, and then medium speed--for a total of about 20 seconds before adding the next. Scrape bowl thoroughly between each addition.
Beat in the vanilla.
On low speed, mix in the dry ingredients in two additions. Mix just until the flour is moistened. The batter will be a little lumpy. That's okay.
Using a whisk, whip the cream until thick. The whisk should leave tracks in the cream that will fill in in a couple of seconds. The cream should still flow it should not be whipped even to soft peaks. This takes about 2 minutes. If you'd rather, you can whip the cream with a hand mixer. Conversely, you can whip the cream in the stand mixer, transferring it to a bowl and holding it in the refrigerator before creaming the butter.
Add the cream and mix it in on low speed for about 5 seconds. Stop the mixer, and finish mixing the batter by hand, folding rather than stirring, until the batter is free of lumps and the cream is gently but thoroughly mixed in.
Scrape the batter into the prepared pan and smooth the top. I usually shake the pan as well to evenly distribute the batter.
Bake on the middle rack until the cake is well risen, golden brown and springs back when touched on the top. You can also test the cake with a wooden skewer or toothpick. If the skewer comes out clean, the cake is done. The cake will just be pulling away from the sides of the pan. This takes about an hour in my oven. I usually turn the pan after about 40 minutes, just to ensure even baking.
Remove from the oven and cool in the pan for half an hour.
Turn out onto a rack and cool completely.
Glaze when cool. Store at room temperature for two days or refrigerate. If refrigerating, make sure to let the cake come to room temperature before serving.