In a blender or food processor, puree 1 cup of fresh raspberries until smooth. Strain the puree through a fine mesh sieve to remove the seeds, yielding about 1/2 cup of raspberry puree. Set aside.

Preheat your air fryer to 325°F. Ensure the pan fits inside the fryer.

In a large mixing bowl, beat 12 room temperature egg whites with an electric mixer on low speed until foamy. Add 1 teaspoon cream of tartar and continue beating on medium speed until soft peaks form.

Gradually add 1 1/2 cups of sugar, 2 tablespoons at a time, while beating on medium-high speed until stiff, glossy peaks form. This should take about 4-5 minutes.

In a separate bowl, sift together 1 cup cake flour, 1/4 teaspoon salt, and 1/4 cup of the sugar (reserve 1 1/4 cups for whipping). Gently fold the flour mixture into the egg white mixture in three additions using a spatula, being careful not to deflate the batter.

Gently fold in 1 teaspoon vanilla extract and the reserved 1/2 cup raspberry puree until just combined.

Spoon the batter into an ungreased angel food cake pan (or air fryer-safe pan) that fits your air fryer. Smooth the top. Place the pan in the preheated air fryer and cook at 325°F for 30-35 minutes, or until the top is golden and a toothpick inserted comes out clean.

Immediately invert the pan onto a cooling rack or bottle neck to cool upside down for at least 1 hour to prevent collapsing.

Once cooled, run a knife around the edges and carefully remove from the pan. Slice and serve with whipped cream or additional fresh raspberries if desired.