Add the dry ingredients in a bowl: whole wheat four, protein powder, pumpkin pie spice, baking soda and salt and mix well. In a separate add the remaining wet ingredients: milk, canned pumpkin, Greek yogurt, avocado oil, honey and vanilla extract and mix well.
Create a well in the dry ingredients to pour the wet mixture into and mix together with a whisk or spoon being careful to not over mix. Overmixing will cause tough muffins.
Fill 9 muffin tins all the way full and bake for 20-23 minutes or until a knife comes out clean.
Try to get the batter in the muffin tins as soon as possible once the batter is mixed to allow the baking soda to do its best work in leavening the muffins.
You can use any protein powder you prefer. I use a pea protein powder. If you don't like the chalky taste of most protein powders, try a collagen powder since they tend to have no flavor.
Eat within a week if refrigerating. Otherwise, freeze them for up to 3 months. They reheat well!
You don't have to follow the instruction for making 9 muffins. You can definitely break the batter up into a dozen muffins, but to get 8g of protein per muffin, you'll need to pour the batter for 9 muffins exactly. So, if protein matters to you then go for 9; otherwise, don't worry about it!