Orange crunchy top muffins

Something a bit different!! I tried these in order to use up the oranges when we bought the wrong ones and they were no good for the kids really. Turned out so nice I'll def be making them again!
You will need:
330g plain flour
2 teaspoons baking powder
1/4 teaspoon baking soda
1 teaspoon salt
110g sugar
3 tablespoons of grated orange zest
130g melted butter
2 eggs
For topping:
1 tablespoon melted butter
90g brown sugar
1/2 teaspoon cinnamon

1 - Preheat oven to gas mark 4/350c
2 - Mix flour, baking soda, baking powder, salt, sugar and orange peel together in a large bowl.
3 - Stir in the orange juice, melted butter and eggs. The result will be very liquidy rather than the usual cake dough. This is normal.

4 - Pour mixture into muffins cases.
5 - Now make some crunchy topping by mixing 1 tablespoon of melted margarine, 90g brown sugar and cinnamon. Sprinkle some of the mixture onto the top of each muffin.

6 - Bake for 20-25 minutes.