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

Melt the butter for the topping over medium heat. Stir in the sugar until combined, then pour the mixture evenly into the prepared pan.

Arrange the sliced strawberries evenly over the buttery sugar layer.

In a medium bowl, whisk together the flour, baking powder, and salt.

In a large mixing bowl, beat the softened butter and sugar until light and fluffy, about 3–4 minutes.

Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

Alternate adding the dry ingredients and milk to the butter mixture, beginning and ending with the dry ingredients. Mix only until combined.

Carefully spread the batter over the strawberries and smooth the surface.

Bake the Strawberry Upside Down Cake for 35–40 minutes or until a toothpick inserted into the center comes out clean.

Cool the cake in the pan for 10 minutes, then carefully invert it onto a serving plate. Allow it to cool slightly before serving. Dust with powdered sugar if desired.