Preheat oven to 350°F. Generously butter a muffin tin and dust lightly with flour or sugar.
In a blender or food processor, blend all wet ingredients until completely smooth. This step helps create a soft, tender crumb.
In a large bowl, whisk together the dry ingredients.
Pour the wet mixture into the dry and gently fold until just combined. Avoid overmixing. Allow the batter to rest for about 5 minutes.
While the batter is resting, prepare the crumble topping by mixing dry ingredients, then cutting in the cold butter until you have damp, clumpy crumbs. Refrigerate the crumble topping for about 5-10 minutes.
After the batter has rested, fold in the cranberries.
Divide batter evenly between muffin cups. Sprinkle the crumble mixture generously over the muffins.
Bake for 18–20 minutes, until set and lightly golden.
Cool in the pan for 8–10 minutes, then gently twist and remove to a cooling rack.