4egg whitesyou can freeze the yolks for later use in a creme brulee
1cup(200g)granulated sugar
½teaspooncream of tartar
1teaspoonlemon extract
Instructions
Preheat oven to 350 °F (177 °C). Line a muffin pan with baking cups and set aside.
In a small food processor, pulse the granulated sugar until it's super fine. If you don't want to do that, you can also buy castor sugar. Sift HALF of the sugar, cake flour, and salt into a medium bowl.
In the bowl of a stand mixer fitted with the whisk attachment, whisk together the egg whites, warm water, lemon extract, and cream of tartar for about 2 minutes.
While the mixer is on medium speed, carefully add the remaining granulated sugar to the mixture then beat until medium peaks form. Remove the bowl from the stand mixer and dust the top of the egg mixture with some of the flour mixture. Using a spatula, gently fold the flour mixture with the egg white mixture until it's all combined. Repeat until all the flour mixture has been incorporated. DO NOT dump all the flour mixture in at once. That will not create a light and fluffy batter.
After all the flour mixture has been incorporated, add 3-4 drops of red food coloring to the batter and gently fold it together.
Divide the batter evenly amongst the prepared muffin pan, filling each until nearly full.
Bake for 18-20 minutes, or until the tops are golden brown and a toothpick inserted in the center comes out clean. Let cool completely on the baking rack before frosting.
While the cupcakes are cooling, to make the marshmallow frosting, put egg whites, sugar, and cream of tartar in a heatproof bowl of a stand mixer and place over a saucepan of simmering water. Whisk constantly until the sugar has dissolved and egg whites are warm to the touch, about 5 minutes.
Return bowl to the stand mixer and using the whisk attachment, beat mixture on low then increasing the speed gradually to high until stiff, glossy peaks form. Add the lemon extract and whisk some more to incorporate.
Frost the cooled cupcakes with the frosting.
Store cupcakes in an airtight container for up to 3 days.