Pumpkin Streusel Muffin

Name: Pumpkin Streusel Muffin
Ingredients: 3/4 cup toasted and chopped pecans; 3/4 cup light brown sugar; 1/2 cup all-purpose flour; 1/2 cup toasted pepitas; 6 tablespoons unsalted butter, melted; Pinch fine salt; Muffins:; 1 cup all-purpose flour; 1 cup light brown sugar; 1/2 cup whole wheat flour; 2 teaspoons baking powder; 1 teaspoon dry ground ginger; 3/4 teaspoon fine salt; 1/2 teaspoon ground allspice; 1/4 teaspoon baking soda; 1/8 teaspoon ground clove; 3/4 cup pumpkin puree; 1/4 cup buttermilk; 2 large eggs; 1 stick unsalted butter, melted (8 tablespoons)