Preheat your oven to 350°F (175°C). Grease an 8-inch baking dish or cake pan with butter. This prevents the cake from sticking and helps the edges turn golden.

In a large mixing bowl, beat the softened butter, granulated sugar and brown sugar. Mix for about three minutes until the mixture becomes light and fluffy.

Add the eggs one at a time. Beat well after each addition. Then mix in the vanilla extract. This step gives the cake a rich and sweet flavor.

In another bowl, whisk together flour, baking powder and salt. Mixing dry ingredients separately helps the cake rise evenly during baking.

Slowly add the flour mixture to the butter mixture. Pour in the milk while mixing. Stir gently until the batter becomes smooth and creamy.

Pour the cake batter into the prepared baking dish. Spread it evenly using a spatula so the cake bakes evenly in the oven.

Place the cake in the preheated oven. Bake for about 35 minutes until the top becomes golden and a toothpick inserted in the center comes out clean.

Remove the cake from the oven and allow it to cool for about 10 minutes. This helps the cake set while still staying warm and soft.

Dust powdered sugar over the top if you like. Some people also drizzle caramel sauce or add a scoop of vanilla ice cream.

Slice the warm butter cake and serve immediately. The inside will be soft and rich while the outside stays lightly crisp.