Meringue Sundae with Peppery Berry Sauce

Name: Meringue Sundae With Peppery Berry Sauce
Ingredients: 1/2 cup frozen strawberries; 1/3 cup frozen raspberries; 3 Tbsp. dark brown sugar; 3 Tbsp. Chambord liqueur; 1/2 tsp. freshly ground black pepper; Pinch of kosher salt; 6–8 small meringue cookies; 3 large scoops vanilla ice cream (from 1 pint); Extra-virgin olive oil, flaky sea salt, and basil leaves (for serving)