Add all the wet ingredients to a blender and blend until smooth and creamy.
Combine all the dry ingredients in a mixing bowl.
Add the blender content to the dry ingredients bowl and combine with a spatula until all is incorporated. Add the chopped walnuts and fold them in. You will get a creamy, thick batter.
Fill the muffin liners with the batter. Bake for 50 minutes in a preheated oven at 350F/180C (maybe a little less if your oven runs hotter). They will be brown on top and no longer soft to touch.
Let them cool for about 30 minutes or more before eating. Dust with inulin powder if you prefer the powdered look. They can be stored in the refrigerator or even frozen.