Ingredients

• 2 cups (480 ml) heavy cream
• 1/2 cup (100 g) sugar
• 1/2 cup (125 ml) water
• 1/4 cup (60 g) unsalted butter, cut into small pieces
• 1/4 teaspoon salt
• 1 teaspoon vanilla extract
• 2 large egg whites
• 1/4 cup (30 g) all-purpose flour
• 1/2 cup (60 g) cake flour
• 1/4 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/2 teaspoon salt
• 1 cup (240 ml) boiling water
• 1/2 cup (100 g) sugar
• 1/2 cup (125 g) unsalted butter, cut into small pieces
• 1/4 teaspoon salt
• 1 teaspoon vanilla extract
• 2 large egg whites
• 1/4 cup (30 g) all-purpose flour
• 1/2 cup (60 g) cake flour
• 1/4 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/2 teaspoon salt
• 1 cup (240 ml) boiling water

Instructions

1. In a medium bowl, combine the heavy cream, 1/2 cup sugar, water, butter, salt, and vanilla extract.
2. In a separate bowl, whisk together the egg whites, all-purpose flour, cake flour, baking powder, baking soda, and 1/2 teaspoon salt.
3. Add the flour mixture to the cream mixture and whisk until smooth.
4. Pour the batter into a 9-inch (23 cm) round cake pan and place in the freezer for 30 minutes.
5. In a medium saucepan, combine the boiling water, 1/2 cup sugar, 1/2 cup butter, and 1 teaspoon vanilla extract.
6. Bring the mixture to a boil over medium-high heat and boil for 2 minutes.
7. Remove the cake pan from the freezer and pour the boiling sugar mixture over the batter.
8. Return the cake pan to the freezer and freeze for 4 hours.
9. Remove the cake pan from the freezer and let stand at room temperature for 30 minutes.
10. Preheat the oven to 425°F (220°C).
11. Bake the cake for 10 minutes.
12. Invert the cake onto a serving plate and serve immediately.