Pumpkin Coffee Cake Streusel Muffins

Name: Pumpkin Coffee Cake Streusel Muffins
Ingredients: 12 Tbs. (1 1/2 sticks) (6 oz./185 g) unsalted butter, melted and cooled slightly; 1 1/2 cups (11 1/4 oz./320 g) firmly packed dark brown sugar; 2 eggs, at room temperature; 2 tsp. vanilla extract; 1 cup (8 oz./227 g) unsweetened pumpkin puree; 1/4 cup (2 fl. oz./60 ml) milk; 2 1/2 cups (9 3/4 oz./300 g) all-purpose flour; 2 tsp. baking powder; 1/2 tsp. baking soda; 1 Tbs. ground cinnamon; 1 Tbs. pumpkin pie spice; 1 tsp. kosher salt