Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.

In a mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt.

Add softened butter, eggs, vanilla extract, and milk to the dry ingredients. Mix until smooth.

Pour the batter into the prepared cake pan and smooth the top.

Bake in the preheated oven for 25-30 minutes or until a toothpick inserted in the center comes out clean.

Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

In a mixing bowl, beat the softened butter until creamy.

Gradually add powdered sugar, mixing until well combined.

Add vanilla extract and milk, mixing until the frosting is smooth and spreadable.

Once the cake is completely cool, spread the frosting evenly over the top and sides of the cake.

Decorate with sprinkles or fruit as desired.