Preheat oven to 180°C (350°F). Line an 8-inch round cake tin with parchment paper.
In a mixing bowl, sift together plain flour and baking powder. Set aside.
Using an electric mixer or whisk, cream the softened butter and condensed milk until light and fluffy.
Gradually add eggs, one at a time, mixing well after each addition.
Gently fold in the dry ingredients in batches, alternating with whole milk and vanilla essence.
Mix until just combined to avoid overworking the batter.
Pour the batter into the prepared cake tin and smooth the top.
Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the tin for 10 minutes before transferring it to a wire rack to cool completely.
Serve as is, or top with whipped cream and fresh fruit.