• Preheat the oven to 325°F.

Make the Cake Batter:

• Separate the eggs, putting the yolks in a small bowl and the whites in the bowl of a stand mixer. Set aside the egg whites to allow them to come to room temperature while you make the batter.
• In a separate large bowl (12-cup capacity or larger) sift the flour, sugar, baking powder and salt together. Then, add the egg yolks, oil, water, lemon zest, lemon juice.
• Using a large spatula whisk, mix the batter until very smooth (don’t use a hand mixer here).
• In the bowl of a stand mixer, add the cream of tartar and whip the egg whites using the whip attachment.
• Starting on a medium speed (speed #6) and increase up to a high speed every 15 to 20 seconds, beating until stiff peaks form, 4 or 5 minutes. The egg whites should look shiny and glossy and stand tall when taking the whip attachment off.
• Add ⅓ of the whipped egg whites to the cake batter and gently fold using a spatula.
• Continue adding the remaining egg whites into the cake batter until just combined. Don’t overmix - you don’t want to lose the air from the egg whites.

Bake the Chiffon Cake:

• Pour the batter into an ungreased angel food tube cake pan.
• Bake for 45 to 55 minutes, or until the cake springs back and a cake tester or wooden skewer comes out clean.
• Immediately invert the pan upside down onto a cooling rack and allow to cool for 30 to 45 minutes before removing the pan.
• Once the cake is released from the pan, set it on a cake stand and make the glaze.

Glaze the Chiffon Cake:

• In a medium mixing bowl add the butter and microwave at half-power for 1 to 2 minutes, until melted.
• Add the lemon zest, powdered sugar, and lemon juice and whisk together until smooth.
• Immediately pour the glaze over the cake, spreading it with a spatula.
• Let the glaze set at room temperature for 20 to 30 minutes before serving.