Mix dry ingredients together and set aside.
In a large bowl combine sugar, butter, eggs, and mix well.
Once incorporated, mix in sour cream/or yogurt and milk.
Then slowly add dry mixture to wet, mixing well. Use a whisk if needed to get out any clumps.
Mix in pumpkin until well incorporated.
Once mixed, use a large kitchen scoop or spoon to spoon batter into prepared muffin tins. Fill about ¾ full.
Sprinkle 1-2 tablespoons of crumb topping over each muffin. Bake in preheated oven for 20-25 minutes until tops spring back and/or until a toothpick inserted comes out clean.
Once slightly cooled, remove from tin and enjoy!