Preheat the oven to 375°F (190°C).
Place the flour and 1 cup (200g) of superfine sugar in a food processor and pulse until aerated, fine and powdery. Then sift into a large bowl and set aside.
In a large mixing bowl, using an electric mixer fitted with a whisk attachment, whisk egg whites, cream of tartar, salt, vanilla extract, and almond extract if used, on medium-low speed until foamy, about 1 minute. Then increase the speed to medium-high and add the remaining ¾ cup of sugar, one tablespoon at a time. Mix until glossy and stiff peaks form, about 5-6 minutes.
Add the flour mixture, ½ cup at a time, and gently fold with a rubber spatula after each addition. Don't overwork the batter, or the cake could deflate. Fold just until combined.
Spoon the batter into a 9 or 10.5-inch (23 or 27cm) springform tube or tube pan.* To remove any air bubbles, run a knife (take care not to scratch the pan) or wooden skewer through the batter and bake for about 35-45 minutes or until golden brown and the top bounces back to the touch.
Then remove the cake from the oven and cool it on a wire rack upside down for about 3-4 hours. To remove the cake from the pan, run an offset spatula around the edges, and remove the springform pan's ring, or tap the tube pan on the counter upside down until the cake comes out. Cut with a long, sharp knife and dust with powdered sugar if desired. Store leftovers in an airtight container in the refrigerator for up to 3 days. Freeze for up to 1 month.