Festive Shrimp Toast

Name: Festive Shrimp Toast
Ingredients: 4 tablespoons unsalted butter, at room temperature; 3/4 to 1 baguette, split lengthwise, then cut into 3-inch pieces; Kosher salt; 4 cloves garlic, minced; 2 scallions, roughly chopped; 2 teaspoons chopped fresh ginger; 1/3 cup mayonnaise; 1/2 teaspoon sugar; 1 tablespoon toasted sesame oil; 1 tablespoon soy sauce; 1 tablespoon rice wine vinegar; 3/4 teaspoon kosher salt; Pinch crushed red pepper flakes; 1 pound large shrimp, peeled, deveined and tails removed; 1 tablespoon sesame seeds; Fresh cilantro leaves, for garnish