Cake

1. Preheat oven to 350 degrees F
2. In a food processor spin the sugar until superfine about 2 minutes
3. Sift half the sugar with salt and cake flour
4. Set remaining sugar aside
5. In a stand mixer, using a ballon whisk attachment, combine egg whites (make sure there is no trace of yolks), water, lemon or orange extract, and cream of tartar and beat on medium speed
6. Once the mixture becomes frothy, slowly sift in the reserve sugar. Continue to beat the eggs until medium stiff peaks form.
7. Sift the flour mixture onto the egg mixture in small amounts at a time (just enough to dust the top of the egg mixture). Using a spatula, gently fold the flour mixture into the egg mixture until incorporated (be careful to not over mix). Continue this process until all of the flour mixture has been incorporated into the egg mixture.
8. Place the batter into an angel food cake baking pan (do NOT grease or oil the sides of the pan.
9. Bake for 30-35 mins
10. Cool, upside down, on a cooling rack for 1 hour before removing from pan (this keeps the cake from collapsing as it cools, allowing for a light fluffy texture)

Blueberry Puree

1. Puree the blueberries, sugar, and lemon juice in a blender
2. Place in a jar with a tight lid
3. Save in the fridge for up to 2 weeks