Oat-Streusel Topping: In medium bowl, mix flour, oats, Truvía® Brown Sugar Blend and cinnamon. Cut in firm butter, using pastry blender or fork, until crumbly.Muffins: Heat oven to 400°F. Line 12 medium muffin cups with paper liners or grease with butter or shortening. Make Oat-Streusel Topping; set aside. Combine egg, oil Truvía® Brown Sugar Blend, and buttermilk in medium mixing bowl. Mix flour, soda, cinnamon and salt in small bowl. Add to mixture in large bowl. Fold in peaches. Divide batter evenly among muffin cups; sprinkle with Oat-Streusel Topping. Bake 18-20 minutes or until lightly browned and toothpick inserted in center comes out clean.