Preheat the oven to 350°F. Line a standard muffin tin with paper liners.

In a medium bowl, sift together the cake flour and ¾ cup of the granulated sugar. Set aside.

In a large mixing bowl, beat the egg whites with an electric mixer on medium speed until foamy. Add the cream of tartar and salt, then increase the speed to high and beat until soft peaks form.

Gradually add the remaining ¾ cup of sugar, continuing to beat until stiff peaks form. Mix in the vanilla extract and almond extract, if using.

Gently fold the flour mixture into the egg whites in three additions, being careful not to deflate the batter. Use a rubber spatula to fold until just combined.

Spoon the batter evenly into the prepared muffin tin, filling each cup about ¾ full.

Bake for 15-18 minutes, or until the tops are lightly golden and a toothpick inserted into the center comes out clean.

Remove the cupcakes from the oven and let them cool in the pan for 5 minutes. Carefully transfer them to a wire rack to cool completely.