🍰 Hot Water Sponge Cake with Quick Caramel Frosting
This Hot Water Sponge Cake is ultra-light and springy thanks to hot water whipped into the batter—a trick that gives it an ethereal texture. It’s paired with a rich and creamy Quick Caramel Frosting, making it a timeless treat for birthdays, holidays, or teatime.
Equipment
- Mixing bowls
- Electric mixer or whisk
- 9x13-inch baking pan or two 8-inch round cake pans
- Saucepan
- spatula
Ingredients
For the Hot Water Sponge Cake:
- 4 large eggs room temperature
- 1 cup granulated sugar
- 1 teaspoon vanilla extract
- 1 cup all-purpose flour
- 1 teaspoon baking powder
- ½ teaspoon salt
- ½ cup hot water not boiling, just very hot
For the Quick Caramel Frosting:
- ½ cup 1 stick unsalted butter
- 1 cup packed light brown sugar
- ÂĽ cup milk whole or 2%
- 1 ½ to 2 cups powdered sugar sifted
- ½ teaspoon vanilla extract
- Pinch of salt optional
Instructions
Make the Sponge Cake:
- Preheat oven to 350°F (175°C). Grease and flour your baking pan(s).
- Beat eggs and sugar together in a large bowl until thick, pale, and tripled in volume (about 5–7 minutes with a mixer on high speed).
- Add vanilla and mix to combine.
- Sift flour, baking powder, and salt together. Gently fold dry ingredients into egg mixture in 2–3 additions, being careful not to deflate the batter.
- Stir in hot water quickly but gently until incorporated. Batter will be thin and airy.
- Pour into prepared pan(s) and bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean.
- Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before frosting.
🥄 Make the Quick Caramel Frosting:
- In a medium saucepan, melt butter over medium heat. Stir in brown sugar and cook for 2 minutes, stirring constantly until bubbly.
- Add milk and bring the mixture to a gentle boil. Simmer for 1 minute, then remove from heat.
- Stir in vanilla and salt (if using). Let cool for 5 minutes.
- Gradually whisk in powdered sugar until smooth and spreadable. If too thick, add a teaspoon of milk at a time. If too thin, add a bit more powdered sugar.
Notes
đź’ˇ Tips for Success
Beat the eggs and sugar long enough to build air into the batter—this is key for sponge texture Add the hot water just before baking to preserve the airiness Work quickly with the caramel frosting—it sets as it cools
Beat the eggs and sugar long enough to build air into the batter—this is key for sponge texture Add the hot water just before baking to preserve the airiness Work quickly with the caramel frosting—it sets as it cools