For the cake:
Cooking spray or unsalted butter, for the baking dish
8 tablespoons (4 ounces) unsalted butter, at room temperature
1 1/2 cups granulated sugar
4 large egg whites, at room temperature
2 1/4 cups all-purpose flour
3 1/2 teaspoons baking powder
1 teaspoon salt
1 cup pink Champagne or sparkling wine, at room temperature
1 teaspoon vanilla extract
Pink gel food coloring

For the syrup:
1 1/2 cups coarsely chopped strawberries
1/2 cup granulated sugar

For the frosting:
8 tablespoons (4 ounces) unsalted butter, at room temperature
1 3/4 to 2 cups powdered sugar, divided
1/2 teaspoon vanilla extract
1 tablespoon pink Champagne or sparkling wine
Pink gel food coloring
Pearl sugar, for garnish (optional)