Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C). Grease an 8-inch round cake pan with cooking spray.

Beat together 1 cup sugar and butter in a large bowl using an electric mixer until pale and fluffy, 5 to 7 minutes. Add eggs one at a time, beating well after each addition. Beat in vanilla until incorporated.

Whisk together flour, baking powder, and salt in a medium bowl. Add flour mixture to butter mixture alternately with sour cream, beginning and ending with flour mixture. Beat until just combined after each addition.

Fold in strawberries.

Spread batter into the prepared cake pan. Sprinkle remaining 1/4 cup sugar evenly over the top.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, 40 to 50 minutes. Let cool completely on a wire rack. Slice and enjoy!