'- Caramel syrup- 280 gram (1 cup + 6 tablespoon) sugar- 100 ml water + 250 ml water- Cake- 145 gram (1 cup + 3 tablespoon) all-purpose flour- 2 1/2 teaspoon baking soda- 1/4 teaspoon salt- 115 gram (1/2 cup) unsalted butter, room temperature- 6 egg yolks- 6 egg whites- 2 teaspoon vanilla essence- 200 gram (1/2 can) sweetened condensed milk

Caramel syrup1. Boil sugar and 100 ml water in a saucepot over medium heat. Continue cooking until the sugar melts and the color is light amber.2. Reduce the heat to low and continue cooking until it starts to caramelize. The syrup will bubble rapidly and the color turns darker.3. Immediately take the pot off the heat. After 30 seconds, pour the remaining 250 ml water into the pot. Wait 5 minutes, then stir until all the caramel dissolves.4. Transfer the syrup to a bowl and cover with a saran wrap. Let it cool in a fridge. (*)Cake1. Preheat the oven to 180 Celsius (350 Fahrenheit). Grease and flour an 8"x8" square cake pan and set aside.2. Sift together all-purpose flour, baking soda, and salt in a mixing bowl. Set aside.3. In a large mixing bowl, cream butter with a mixer with medium speed. Add egg yolks, one at a time, and beat until well combined. Add 1⁄3 of the egg whites (2 egg whites) and continue mixing until well combined, then add the rest of the egg whites (4 egg whites) and continue mixing until well combined.4. Add vanilla extract into the batter and mix until well combined.5. Set the mixer to low speed. Add the flour mixture in two batches, beating each addition until well combined. Add sweetened condensed milk, mix until well combined.6. Pour the cooled caramel syrup into the batter. Fold with a spatula until well combined.7. Pour the batter into the prepared cake pan. Bake the cake on the lower third of an oven for one hour, or until a cake tester comes out clean.8. Cool the cake in the pan, then cut into serving slices and serve at room temperature.