This recipe makes 24 tarts.

1. Preheat oven to 180°C or 350°F and grease 2 muffin pans.
2. In a bowl combine flour, baking powder, salt and orange zest.
3. In a separate bowl combine eggs and sugar and beat with an electric mixer for 3 minutes or until the eggs are pale yellow and fall in ribbons, stir in orange juice, butter and vanilla  until well combined.
4. Stir in the dry ingredients and stir well until it's well combined.
5. Pour the batter into the muffin cups filling them 2/3 of the way up.
6. Bake for 13-15 minutes or until the edges start to brown.
7. Sprinkle the top of each tart with some coarse sugar and place the pans back in the oven.
8. Turn the oven off and leave them in there for 2 minutes.
9. Allow the pans to cool for 5 minutes then run a knife around the edge of each tart and gently unmold.