Gluten Free Lemon Chiffon Cake

This is a wonderful cake -I got lucky on this one first try!   The combination of flours and changing the egg white and egg yolk amounts from my original recipe made a great cake that you would never guess was gluten free. 
Gluten Free Lemon Chiffon Cake - makes 2 cakes
Set  oven to 325*.  Have two 10" Bundt or tube pans  or one large 10" - 12" Bundt pan and cup cake pans - DO NOT grease pans

Sift together:
1 cup rice flour
1/2 cup tapioca flour
1/2 cup cornstarch
1/4 cup sweet rice flour
3 teaspoons baking powder
1 1/2 cups sugar
1/2 teaspoon salt.
Make a well in the center of the dry mixture.  Pour in:
1/2 cup cooking oil (I used canola oil)
7 large egg yolks
1/2 cup cold water
1/4 cup lemon juice
1 tsp grated lemon rind - optional
Beat with hand mixer until smooth - about 2 minutes.
Clean the beaters well and in a separate glass bowl beat until very stiff:
7 large egg whites
1/2 teaspoon cream of tartar.
Pour the first mixture over the beaten egg whites a little at a time, gently folding it in with a spatula until evenly blended.  Do not beat or stir.  Pour half of batter into each cake pan. 
Put both pans in oven and bake at 325 for 50 minutes until the top springs back when you dent it with your fingers.  Top should be golden brown.  Take from the oven and turn the pans upside down on a wire rack and let stand until cold. 
When cold wrap one of the cakes in plastic wrap and a freezer bag and freeze for another time - eat the other!  Tastes good with a bit of whipped cream, lemon glaze or on it's own.