Pistachio Crunch Muffins

Name: Pistachio Crunch Muffins
Ingredients: 2/3 cup unsalted, raw, shelled pistachios; 1/2 cup all-purpose flour; 1/3 cup packed light brown sugar; 1/8 teaspoon kosher salt; 3 tablespoons cold unsalted butter; 1 1/2 teaspoons vanilla extract; 2 large eggs; 2/3 cup sour cream; 4 tablespoons unsalted butter; 1 1/3 cups unsalted, raw, shelled pistachios, divided; 1 1/2 cups all-purpose flour; 1 1/2 teaspoons baking powder; 1/2 teaspoon kosher salt; 1/4 teaspoon baking soda; 2/3 cup neutral oil, such as canola or vegetable; 3/4 cup granulated sugar; 1 tablespoon vanilla extract; 1 to 2 drops green food coloring (optional); Powdered sugar, for dusting (optional)