Preheat oven to 400°F. Lightly grease or line a 12 cup muffin tin with paper muffin cups.
In a large mixing bowl, whisk flour, baking powder and salt.
In a medium bowl, add sugar and orange zest. Using your fingers, crumble the zest and blend into the sugar. Whisk in the olive/vegetable oil, yogurt, eggs, and orange juice until well combined.
Pour the sugar mixture into the flour mixture, stir just until the flour is blended throughout. Fold in the cranberries. Then using an ice cream scooper, divide the batter among the muffin cups.
Streusel Topping: mix together flour and sugar and then break butter into small pieces into the mixture. Sprinkle lightly on top of each muffin. You may need to flatten the batter to allow the topping to sit on top of the muffins.
Bake muffins for 20-22 minutes ,until golden in colour and a toothpick insert comes out clean. Allow to cool for a few minutes.
Notes
These muffins are best stored in an airtight container at room temperature for up to 2 days, then refrigerate them for one week. They freeze well for up to 2 months.