Preheat oven to 350 F. Line standard-sized loaf pan with parchment paper or use non-stick silicone loaf pan.
In large bowl, mix together flour, protein powder, baking powder, baking soda, cinnamon, nutmeg, and salt. In separate bowl, whisk together sweet potato, peanut butter, milk, maple syrup, and vanilla. Add wet ingredients to bowl with dry ingredients and mix gently until everything is moist. Pour batter into pan and smooth the surface with spatula. Sprinkle peanuts and press them down lightly to adhere.
Bake in preheated oven for 40 minutes, or until a tester inserted into the centre of the loaf comes out mostly clean. Allow loaf to cool in pan for 10 minutes, before cooling further on a metal rack.
Recipe Notes
Per serving: 281 calories; 14 g protein; 12 g total fat (2 g sat. fat); 33 g total carbohydrates (18 g sugars, 4 g fiber); 445 mg sodium