Preheat the oven to 325 degrees F. Line the bottom of a 16-cup tube pan with parchment paper (do not grease).
In a medium bowl, sift the flour and ¾ cup of the sugar (place the remaining ¾ cup of sugar in a separate small bowl).
In the bowl of a stand mixer fitted with the whisk attachment (or an electric hand beater), begin whisking the egg whites over medium-low speed. Add the cream of tartar and salt and whisk until the mixture is foamy (this process should take about 1 minute). Turn the mixer to medium-high speed and whip the egg white mixture to a puffy, frothy cloud-like texture (1 minute). Slowly add the ¾ cup of sugar that you had set aside—a heaping tablespoon at a time—until you achieve soft, glossy peaks (about 2 minutes). Add the vanilla and almond extracts and beat until incorporated (20 to 30 seconds).
Begin adding the sifted flour and sugar mixture to the whipped egg whites—about ¼ cup at a time—and use a rubber spatula to gently fold it into the egg whites. Repeat until all the flour/sugar is incorporated.
Spoon the batter into your prepared tube pan. Swirl a butter knife through the batter to help pop/release any air bubbles and then smooth the top of the cake with a rubber spatula. Bake until the top is golden brown and the cake springs back when you press a finger into the top, 52 to 55 minutes.
Invert the tube pan onto your countertop (especially easy to do if the tube pan has prongs or “feet” on the sides) or onto a wire cooling rack and let cool completely upside down (to prevent deflating). Run a butter knife around the edges of the pan to loosen the cake and then remove it from the pan, peeling off the bottom layer of parchment paper.
Serve slices of angel food cake with sweetened whipped cream and chopped strawberries.
Notes
Recipe adapted from Cooks Illustrated "Best Angel Food Cake"