Preheat the oven to 350°F (176°C). Grease an 8-inch pan and line it with parchment paper.
In a large mixing bowl add egg, whisk them until they are well beaten. Incorporate the condensed milk, beating until the batter is smooth and uniform.
Add the self-rising flour and mix until well combined.
Pour the batter into the prepared pan and bake for 30 minutes or until toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then carefully remove it from the pan and transfer it to a wire rack to cool completely.