245g Natural Yogurt
1tbsp Lemon Juice
Place the egg whites, salt and cream of tartar in a mixer.
Mix on medium power until frothy.
Add the vanilla extract, lemon juice, and lemon zest. Beat on high speed until soft peaks form, about 2 to 4 minutes.
Gradually add the sugar and beat until the mixture forms stiff peaks, about 2 minutes longer.
Sprinkle the flour over the egg white mixture. Using a spatula, carefully fold in the flour until incorporated.
Spoon the batter into an ungreased 10-inch nonstick angel food cake pan. Bake for 30 to 40 minutes until the top is browned and a skewer inserted halfway between the inner and outer wall of the pan comes out clean.
Invert the pan on a wire rack to cool completely, about 1 hour.
For the sauce: In a small bowl whisk together the yogurt, honey, and lemon juice until smooth.
Using a spatula, loosen the cake around the sides and middle. Release the cake and place on a serving plate.
Cut into slices and drizzle with the sauce.