Sift together the flour, ¾ cup sugar, baking powder and salt in a medium bowl.
In a large bowl, use a hand mixer to mix together the egg yolks (you'll use the whites later), water, oil and vanilla. Beat until smooth.
Mix the flour mixture into the egg yolk mixture and mix just until combined.
Add the mashed bananas and mix again just until combined.
In a separate clean bowl, beat the egg whites and cream of tartar together using a high speed hand mixer (or stand mixer) until soft peaks form.
Add the remaining 1/2 cup sugar, then continue beating until stiff peaks form. This will take 3-5 minutes total to whip the egg whites.
Fold the egg whites into the banana cake batter. Continue gently folding the egg whites in until the batter looks evenly mixed.
Pour the batter into an ungreased 10” tube pan.
Bake in the preheated oven for 55 minutes or until the cake springs back when you touch it.
Immediately invert the pan and let it rest upside down on 3-4 glasses. I usually put 3 glasses around the outside and one in the center. If it is a 2-piece angel food cake pan, the bottom may start to come loose so the middle cup helps hold it together until cool.
Allow the cake to cool upside down completely, then slide a knife around the sides and center of the pan to loosen the cake.
Remove the cake to a plate.
To make the glaze, whisk together the sugar, vanilla extract and heavy cream. Add additional heavy cream to get desired drizzling consistency.
Drizzle the cooled cake with the glaze.
Store in an airtight container at room temperature.
Notes
The calories shown are based on the cake being cut into 12 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**