Preheat oven to 350 degrees. Line a 12-capacity muffin tin with baking cups.
Finely shred the zucchini and, using your hands, squeeze out as much moisture as possible. Set aside.
In a large bowl, whisk together the egg, whole milk, dark maple syrup and olive oil.
Add the remaining ingredients, except for the peanut butter, and stir well to combine.
Scoop the batter into the prepared muffins tins.
Add a 1 T dollop of peanut butter to each unbaked muffin and gently swirl into the batter using a knife.
Bake for 15 minutes or until the muffins are cooked through.
Remove from oven and allow to cool.
This recipe was inspired by the Peanut Butter Swirled Double Chocolate Zucchini Muffins by Baked Greens Blog.