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

In a small bowl, combine the sliced strawberries and brown sugar. Let them sit for about 10 minutes to release their juices.

Pour the melted butter into the prepared cake pan, spreading it evenly across the bottom.

Arrange the strawberries over the melted butter in a single layer.

In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, and salt.

In another bowl, mix the milk, egg, and vanilla extract until well combined.

Gradually add the wet ingredients to the dry ingredients, stirring until just combined. Do not overmix.

Pour the batter over the strawberries in the cake pan, spreading it evenly.

Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted in the center comes out clean.

Allow the cake to cool in the pan for 10 minutes, then carefully invert it onto a serving plate. Let it cool completely before slicing.