Preheat oven to 350°F. Grease and line 2 8" round cake pans with parchment paper.
In a mixing bowl, sieve flour, baking powder, baking soda and salt.
In a large mixing bowl, combine oil (or melted and cooled butter) and sugar, beat until the mixture turns light, about 3~4 minutes. Add condensed milk and beat again until well combined.
Add ⅓rd of the flour mixture to the oil mixture and mix until combined. Add ½ of the milk and mix well.
Next add another ⅓rd of the flour mixture, mix and add the remaining milk.
Finally add the remaining flour and mix well until combined.
Divide the batter evenly into the prepared pan and bake in the preheated oven for 30~35 minutes or until a cake tester inserted in the center comes out clean. If the cake seems to be browning too fast, then either cover the pan with aluminum foil.
Let the cakes cool in the pan for 5 minutes. Then remove onto a wire rack to cool completely.