Preheat oven to 375 degrees F. Line muffin pans with paper liners or coat with cooking spray. Set aside.
In a large bowl, whisk together flour, sugars, baking powder, salt, cinnamon, and nutmeg. Set aside.
In a small bowl, whisk together buttermilk, butter, honey, egg, and vanilla. Pour the liquid mixture over the dry ingredients and stir until flour disappears. Gently fold in the peaches.
In a small bowl, combine oats, flour, brown sugar, cinnamon, and butter. Mix topping together with your fingers until you have a crumbly mixture. Stir in the honey and mix until combined.
Fill muffin cups 3/4 of the way full. Sprinkle each muffin with oat streusel topping. Bake for 18-20 minutes or until a toothpick stuck in the middle comes out clean. Let cool for 5 minutes. Serve and enjoy!