Preheat oven to 350℉ and line 2 muffin tins with paper liners.
In a large mixing bowl beat together sugar and eggs. Then add in vegetable oil and pumpkin. Mix together until it is smooth
Then add in cake flour, all purpose flour, baking soda, cinnamon, and nutmeg. Stir until combined. Then fold in the raisins.
Spoon into prepared muffin pan and fill each liner ¾ full.
Streusel:
Combine flour, sugar, brown sugar, cinnamon and salt. Stir and then add in cold butter and mash with a fork until it resembles coarse crumbs. (You can even use your hands to work through the cold butter.)
Sprinkle streusel on top of each muffin. Bake for about 18 minutes or until golden brown.
Frosting:
Beat cream cheese and butter together until smooth. Then add in remaining ingredients and mix until smooth and creamy. (If the frosting is too runny - add a little more powdered sugar)
Pipe icing onto the cooled muffins.
Notes
While we are very partial to the frosting because it is DELISH! But, if you want to omit it you definitely can. Or you can definitely buy premade frosting and use that instead to make it a little simpler.Adapted from Spreading Magic.