Preheat your oven to 350°F (175°C). Grease and flour a 9-inch (23 cm) round cake pan.
In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
Beat in the eggs one at a time, ensuring each egg is fully incorporated before adding the next.
Stir in the vanilla extract.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the butter mixture, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined.
If using, fold in the raisins and chopped nuts.
Pour the batter into the prepared cake pan and smooth the top with a spatula.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.
Dust with powdered sugar before serving, if desired.
Enjoy your meal!