9 tablespoons unsalted butter, softened, plus more for greasing
1 1/2 cups all-purpose flour, plus more for dusting
3 tablespoons cornstarch
1 teaspoon baking soda
1/2 teaspoon salt
1 1/2 cups plus 2 tablespoons granulated sugar
3 whole large eggs
1/2 cup sour cream, at room temperature
1 teaspoon vanilla extract
1 pound strawberries, plus more to garnish, optional

Icing:
1 1/2 pounds powdered sugar, sifted
8 ounces cream cheese, at room temperature
2 sticks unsalted butter, softened
1 teaspoon vanilla extract
Dash salt