Fabulous Orange Choc-Chip Muffins

Ingredients

• 2 cups plain flour
• 2 teaspoons baking powder
• 1/2 teaspoon bicarbonate of soda
• 1/4 teaspoon salt
• 1 cup sugar (can put less if you like)
• 1/4 cup oil (I use sunflower or corn)
• 1 1/2 cups orange juice (freshly squeezed for best results)
• 2 tablespoons orange zest
• 1 egg, beaten
• 100 g dark chocolate chips