Heat an oven to 325 degrees Fahrenheit, and line a 12-muffin tin with cupcake liners or baking cups.
Mix the dry ingredients in a large bowl and set aside.Gradually add the milk, yogurt, oil, and egg to the dry ingredients. Stir until smooth.Transfer the batter to the cupcake liners as evenly as possible. Each liner should be around 3/4 full.
Bake for 20-22 minutes or until a toothpick comes out clean. Avoid overcooking as protein treats run a higher risk of being dry/tough with overcooking.While your protein cupcakes cool, mix the frosting ingredients in a bowl with a handheld or standing mixer.
Once the cupcakes have cooled completed, frost your cupcakes, and enjoy!