Yes! You can make a streusel for these pancake mix muffins! You will want to follow the following steps.  Add ½ teaspoon of ground cinnamon to the batter.  Then measure ½ cup of all-purpose flour, ¼ cup packed brown sugar, ½ teaspoon of ground cinnamon, and 3 tablespoons of butter, cut into cubes.  Mix the flour, sugar, and brown sugar. Then cut the butter into the mixture until you have small crumbs.  Sprinkle the streusel mixture evenly over the tops of each muffin cup. Each will get about 2 tablespoons of the streusel.  Gently press the topping into the muffin batter, then back according to package directions.