Prepare egg mixture: Beat 4 eggs with 1 tablespoon of vanilla extract. Add 1 cup of fine white sugar and mix well until the sugar dissolves completely.
Add oil: Add 1/2 cup of vegetable oil to the egg and sugar mixture and continue stirring to combine.
Sift dry ingredients: Sift together 2 1/2 cups of all-purpose flour and 2 1/2 teaspoons of baking powder. Gradually add the sifted flour mixture to the wet ingredients, stirring gently in one direction until combined.
Prepare milk and butter mixture: In a separate bowl, combine 1 cup of boiling milk with a pinch of salt and 1/2 cup of butter. The butter will melt in the hot milk.
Combine milk mixture and vinegar: Add the hot milk and melted butter mixture to the cake batter while continuing to beat. Then add 1 tablespoon of vinegar and mix until the batter reaches a smooth consistency.
Prepare baking pan: Grease a cake pan thoroughly with margarine, butter, or oil, including the sides. Lightly sprinkle flour over the greased pan and distribute evenly.
Bake the cake: Pour the batter into the prepared pan. Bake in a preheated oven at 180°C (356°F) on the middle rack with heat from the bottom only. Bake until a toothpick inserted in the center comes out clean, approximately 30-40 minutes.
Serve: Let the cake cool slightly. Serve with tea, milk, or pour a little milk over the cake. Optionally, enjoy with light jam and a sprinkle of sugar for added sweetness.