Preheat the oven to 330°F (165°C).
Pulse the granulated sugar into fine sugar. Use a food processor or blender.
Put ¾ cup of aquafaba from a can of chickpeas into a large mixing bowl with cream of tartar and vanilla extract. Beat for at least 6 minutes with a hand mixer, first on low and then gradually increasing the speed to high.
Add the powdered sugar slowly while continuing to beat the meringue on high for another 1-2 minutes.
After you have beaten the aquafaba for at least 8 minutes, add a tablespoon of chickpea flour and beat for another minute.
In 3 additions, slowly sift the flour mixture into the egg white mixture using a fine mesh strainer, gently folding with a rubber spatula after each addition. To avoid deflating or a dense cake, don’t add the flour mixture all at once. Sift and very slowly fold in several additions.
Pour and spread batter into an ungreased 9 or 10 inch tube pan. Shimmy the pan on the counter to smooth down the surface.
Bake the cake until a toothpick inserted comes out clean, about 45-50 minutes. Rotate the pan halfway through baking.
Remove from the oven, then cool the cake in the pan for about 3 hours.
Once cooled, run a thin knife around the edges and gently tap the pan on the counter until the cake releases.
If desired, dust with confectioners’ sugar. Slice the cake with a sharp serrated knife.
Serve with fresh berries and a dollop of whipped cream.