In a small bowl, whisk together the 1-to-1 flour, vanilla protein powder, quick-cooking oats, pumpkin pie spice (or spice mixture), baking soda and salt. Set aside.
In a large stand mixer or bowl with a hand mixer, cream together the softened butter, granulated sugar, and light brown sugar. Crack the egg into a separate bowl or mug first before adding to the mixing bowl to prevent any bad eggs or shells getting into the batter. Beat the egg and vanilla with the butter and sugar until fully combined.
Stir in the flour mixture slowly, alternating with the pumpkin puree, stirring just until combined. Stop occasionally to scrape the bottom and sides of the bowl to make sure everything is stirred together properly. Then finely chop the washed cranberries in a food chopper or processor and stir into the batter.
Preheat the oven to 350*F and line your muffin tins with muffin cup papers or spray with non-stick spray (such as Pam) to prevent batter from sticking.
Use a spoon or cookie scoop to spoon the dough into the prepared muffin tins. Bake until the muffins are golden brown, about 25 minutes, or until a toothpick poked into the center comes out clean with no crumbs. Let cool on a baking sheet on top of a wire rack.
