Preheat your oven to 375°F (190°C) and line your muffin tin with paper liners.
In a large mixing bowl, whisk together the flour, sugar, baking powder baking soda, and cinnamon.
Wash the orange well, because you will be using the peel. Cut the orange into chunks, leaving the peel on. Remove any seeds and place the orange pieces in a blender or food processor. Add the orange juice and blend until smooth. Add the egg, butter, and vanilla, Blend again until smooth. You may have to scrape the sides of the blender with a spatula a couple of times.
Pour the wet ingredients into the flour mixture and gently fold until just combined. Gently fold in the cranberries and chopped pecans until evenly distributed.
Using a spoon or an ice cream scoop, fill each muffin cup about 3/4 full with the muffin batter.
Mix the brown sugar, cinnamon and flour together. Add the softened butter and mix until crumbly. Add cranberries and chopped pecans if desired. Sprinkle the topping over the tops of the muffins. Extra topping may be stored in the refrigerator for future baking projects.
Place the muffin tin in the preheated oven and bake for 15-17 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Allow them to cool in the tin for 5 minutes before transferring to a wire rack to cool completely.