Begin by gathering all your ingredients and placing the frozen strawberries in the blender. If you're using any optional add-ins, add them at this step as well.
Next, add the protein powder of your choice, the milk, nut butter, and vanilla extract to the blender. If you prefer a sweeter shake, add your desired sweetener now.
Blend the mixture on high speed until smooth and creamy. If the shake is too thick, you can add a little more milk to reach your desired consistency.
Once blended, taste the shake and adjust sweetness or flavors if necessary. If you want a thicker texture, consider adding more frozen strawberries or a spoonful of cottage cheese.
Pour the shake into a glass and garnish with fresh strawberries if desired. Enjoy your nutritious and delicious strawberry protein shake!