Any Berry Galette

Name: Any Berry Galette
Ingredients: 1½ tsp. sugar; ¾ tsp. kosher salt; 1⅓ cups (180 g) all-purpose flour, plus more for surface; ¾ cup (1½ sticks) chilled unsalted butter; 2 tsp. cornstarch; 1 tsp. finely grated lemon zest; 1 tsp. kosher salt; 1 tsp. freshly ground black pepper (optional); ⅓ cup sugar, plus more for sprinkling; 2 lb. strawberries or other berries, hulled, halved if large; 1 Tbsp. fresh lemon juice; 1 tsp. vanilla extract; 1 Tbsp. heavy cream; Softly whipped cream or vanilla ice cream (for serving; optional)