Ingredients
- 4 egg yolks
- 3/4 cup sugar
- 2 tablespoons cold water
- 1 stick butter, melted
- 3/4 cup flour
- 1/8 teaspoon salt
- 2 cups whole milk or half and half (I used half and half)
- 2 teaspoons vanilla
- 4 egg whites, at room temperature
Here’s how to make it:
- Cut two pieces of parchment paper so they fit into the bottom of an 8-inch square baking pan and overlap the edges. Spray the bottom of the pan with nonstick cooking spray, then lay the first piece of parchment paper inside. Lay the second piece going the other way. This will make it easy to remove the cake once baked.
- Put the egg yolks, sugar and water into the bowl of a stand mixer (you could also use a mixing bowl and handheld electric mixer). Beat until it turns pale yellow and is fluffy, at least 5 minutes. Don’t undermix.
- Slowly add in the melted butter.
- Stir in the flour and salt. Scrape down the sides of the bowl. Pour in the milk and vanilla and mix on low until combined.
- In another bowl, beat the egg whites until stiff peaks form, about 2 to 3 minutes.
- Gently fold the egg whites into the egg yolk mixture. Do not overmix. You want to leave some unincorporated clumps on the top of the batter.
- Pour the batter into the prepared baking pan.
- Bake in a preheated 325-degree F oven for about 50 minutes. The top should be golden brown but the center should still jiggle. Cool the cake on the counter until it’s at room temperature, then cover and refrigerate at least 4 hours.