01 - Preheat oven to 350°F. Lightly grease or line a 9x5-inch loaf pan with parchment paper.
02 - Whisk together whole wheat flour, whey protein powder, light brown sugar, ground cinnamon, baking powder, baking soda, and salt in a large mixing bowl. Stir in raisins.
03 - In a separate medium mixing bowl, whisk unsweetened almond milk, Greek yogurt, eggs, melted coconut oil, and vanilla extract until fully incorporated and smooth.
04 - Pour wet ingredients into dry ingredients and fold gently with a spatula until just combined. Avoid overmixing the batter.
05 - Spoon batter into prepared loaf pan and spread evenly to smooth the top.
06 - Place pan in oven and bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out clean.
07 - Allow loaf to cool in the pan for 10 minutes before transferring to a wire rack to cool completely. Slice when fully cooled.