Preheat the oven to 350 degrees F. Spray a nine-inch round cake pan with cooking spray and set aside.
Combine butter and one cup of sugar in a mixing bowl. Beat with electric mixer for five minutes or until mixture is light and fluffy.
Add eggs, one at a time, beating well after each addition. Beat in the vanilla.
In a separate bowl, whisk together the flour, baking soda, and salt. Add ⅓ of the flour mixture to the butter mixture and mix well. Add ½ the sour cream and mix. Again, mix in ⅓ of the flour mixture, followed by the rest of the sour cream. Mix in the remaining flour mixture.
Fold in the strawberries. Spread batter into prepared pan.
Sprinkle remaining sugar on top of batter.
Bake at 350 degrees F for 45 minutes or until toothpick inserted in center comes out clean.
Let cake cool completely. Serve straight from the pan with a dollop of whipped cream.