Preheat oven to 350 degrees F. Line a 6-cup standard muffin tin with paper liners; set aside.
In a large bowl, combine flour, oats, baking powder, pumpkin, apple sauce, vegetable oil and eggs. Stir in carrots.
Scoop the batter evenly into the muffin tray. Place into oven and bake for 15-20 minutes, or until a tester inserted in center comes out clean. Remove from oven and cool completely on a wire rack before frosting.
In a medium bowl, combine cream cheese and peanut butter.
Use a small offset spatula or a pastry bag fitted with decorative tip #1M to frost the cupcakes, garnished with Milk-Bone, if desired.