Adjust oven racks to the top and lower third positions then preheat oven to 350 degrees.

Add gluten free flour blend and cornstarch to a bowl then whisk to combine and set aside.

Add granulated sugar to a blender or food processor then blend/pulse briefly to create super-fine sugar. We’re not looking to make powdered sugar, but a finer sugar texture will dissolve faster and easier in the cake batter than regular granulated sugar.

Add egg whites, cream of tartar, and salt to the bowl of an electric stand mixer fitted with the whisk attachment, or to a large glass bowl if using a hand held mixer, then beat on medium speed (6/10) until the egg whites are very foamy, 1 minute. Add vanilla then beat to combine.

Set the speed to medium-low (4/10) while slowly but constantly sprinkling in the super-fine sugar. Once all the sugar has been added, turn the speed up to medium-high (8/10) and continue to beat until the egg whites are glossy and medium peaks have formed (meaning, when you lift the whisk attachment, the batter holds its shape but the tip droops slightly), 3-4 minutes total.

Add flour and corn starch mixture in three additions, beating until just combined before adding the next addition.

Use a spatula to give the cake batter a big stir to ensure all the ingredients are well mixed then scoop into an UNGREASED nonstick angel food cake pan. Smooth the top with the back of a spoon or an offset spatula then bake for 45-47 minutes or until the top is deep golden brown. It’s better to slightly overbake vs underbake this cake, as it can collapse if underbaked.

Immediately invert the pan over a bottle — I use a wine bottle covered in foil. You could use an empty, clean soda bottle or vinegar bottle, etc. covered in foil. Some angel food cake pans have extended feet on the top of the pan so you can turn it over directly onto the countertop.

Let cake cool completely. The cake can sag if released from the pan before it’s completely cool.

Once cake has completely cooled, turn the pan right side up then run a knife around the inside and outside edges to release the cake. Slice into wedges with a serrated knife then serve with whipped cream and fresh berries.