Preheat oven to 350 degrees F. Grease a 9-inch cake pan.

Beat the butter and sugar together in a large mixing bowl with an electric mixer on medium speed for 3 minutes or until pale and fluffy. 

Add the egg, milk, and vanilla to the bowl and mix till combined. 

Stir together the flour, baking powder, and salt in a bowl till combined. Then add half the dry mixture into the wet mixture. Stir till flour is incorporated. Add the remaining dry mixture and stir to combine. Beat for 1 minute until the batter is fluffy. 

Pour the batter into the cake pan and spread till you have an even layer. 

Place the raspberries on top in a single layer. Sprinkle additional 2 teaspoons of sugar on top. 

Bake for 50 to 60 minutes. Test the cake with a wooden skewer or cake tester to see if the center is fully baked before removing it from the oven. 

Let the pan cool on a wire rack for at least 20 minutes before removing the cake and cutting.