Preheat your oven to 350°F (175°C). Ensure the oven rack is positioned in the lower third of the oven.
Sift the cake flour and 3/4 cup of granulated sugar together three times to aerate and combine thoroughly. Set aside.
In a large, clean, and dry mixing bowl, beat the egg whites with an electric mixer on medium speed until foamy. Add the cream of tartar and salt, and continue beating until soft peaks form.
Gradually add the remaining 3/4 cup of granulated sugar, about 2 tablespoons at a time, beating on high speed until stiff peaks form and the mixture is glossy.
Fold in the vanilla extract, lemon zest, and lemon juice gently with a rubber spatula, taking care not to deflate the egg whites.
Sift the flour-sugar mixture over the egg white mixture in three additions, gently folding after each addition until just combined.
Pour the batter into an ungreased 10-inch tube pan. Smooth the top with a spatula and run a knife through the batter to remove any large air pockets.
Bake for 35-40 minutes, or until the top is golden brown and springs back when lightly touched. Invert the pan immediately and let cool completely, about 1-2 hours.
Once cooled, run a knife around the edges and center tube to loosen the cake. Remove from the pan and serve.