Preheat the oven to 350°F. Spray an 8.5×4.5 loaf pan with baking spray.
In a bowl, add sugar and zest the clementines over it using a microplane. Rub the zest into the sugar with your fingers until the oil is released and fragrant.
Peel the clementines, cut out the segments, and set aside on a paper towel.
In a medium bowl, whisk together the flour, baking powder, and salt.
Whisk the yogurt into the sugar mixture.
Add eggs one at a time, beating vigorously until smooth. Stir in vanilla and orange extract.
Add the dry ingredients and whisk until just combined.
Use a spatula to stir in the olive oil and clementine segments.
Pour the batter into the prepared loaf pan and sprinkle with sanding sugar if desired.
Bake for 50–60 minutes, or until a toothpick comes out clean.
Cool for 5 minutes before transferring to a wire rack to cool completely.