1.To prepare an 9-inch springform pan, add a piece of parchment paper at the bottom and around the sides. Set aside. Separate egg whites into the bowl of a standing mixer, and yolks in a large bowl.
2.Using the stand mixer with a whisk attachment, beat the egg whites with the cream of tartar until soft peaks. Next, gradually add 1/4 cup sugar and continue beating until stiff peaks form, set aside.
3.Preheat oven to 340 degrees. In a small bowl add flour, salt, and baking powder. Whisk and set aside.
4.In the bowl with egg yolks, use a whisk to combine with 2/3 cups sugar, beat well till light and fluffy. Then, add mango puree and oil, continue beating. Next, add the lemon juice, and vanilla. Add in flour mixture and mix well making sure there are no lumps.
5.Add the egg whites to the yolk mixture in 4 batches. Carefully fold in the egg whites each batch until it is incorporated. Once the batter is ready, pour it into prepared pan. Tap on the counter to release bubbles. Bake for 60 mins, the cake should spring back when pressed in the center.
6.Once cake is done let it cool on a wire rack before removing it from the pan.