Preheat your oven to 350°F (175°C) to ensure it’s ready for those cookies, so they bake evenly and come out golden on the edges.
In a bowl, sift together oats, flour, protein powder, baking soda, salt, and cinnamon.
Sifting helps avoid lumps and makes sure everything blends well. If you’re in a rush, just whisk it all together!
In a large mixing bowl, cream together the melted butter, brown sugar, and granulated sugar until smooth.
Add in the egg and vanilla extract and mix until everything is well combined.
Slowly add the dry mixture to the wet ingredients and stir gently until combined. Don’t overmix, just make sure everything is incorporated and there are no streaks of flour left.
Now, fold in those juicy raisins (and nuts, if you’re adding them).
Use a cookie scoop (or your hands) to form 1-2 tablespoon-sized dough balls and place them on a parchment-lined baking sheet, leaving some space between each one.
Bake for 10 minutes, until the edges are golden and the center is just slightly soft.
Let the cookies cool on the baking sheet for a few minutes, then transfer them to a wire rack to cool completely.
Now you’ve got a batch of delicious, soft, and chewy protein oatmeal raisin cookies ready to enjoy!