Preparation

To make the cake

• Position a rack in the lower third of the oven and preheat oven to 350°F. Sift together half of the sugar and flour into a medium bowl.
• In the bowl of a stand bowl mixer fitted with the whisk attachment, beat egg whites, cream of tartar, and salt on medium-high speed until mixture holds soft peaks, 2 to 3 minutes. With the mixer still running, slowly pour in the remaining sugar and beat until mixture is glossy and holds stiff peaks. Beat in vanilla bean paste.
• Sift flour mixture in three additions into egg-white mixture, gently folding after each addition to incorporate. Scrape batter into a 10-inch angel food cake pan with a removable bottom and smooth the top with a spatula. Bake for 40 to 45 minutes, or until cake is deeply golden with a deep crack in the surface and a toothpick inserted into the center comes out with just a few moist crumbs (a metal tester will come out clean even if cake is not done). Invert the pan onto the bottle and let cool completely. Run a thin spatula along the sides and around the center of the cake to loosen from pan and transfer to a serving platter.

To make the frosting

• To make the frosting, beat together cream cheese and white chocolate in the bowl of a stand mixer until smooth and creamy. In a separate bowl, whip together cream, vanilla extract, and vanilla bean paste until stiff peaks form. Gently stir about one-third of the whipped cream into the cream cheese mixture to lighten it, then gently fold in the remaining whipped cream.
• Frost the cake generously, using the back of a tablespoon to create swoops and swirls.