1 1/3 cups sugar
½ cup and 3 tablespoons cake flour
6 tablespoons and 1 teaspoon durum wheat flour
6 tablespoons and 1 teaspoon all-purpose flour
2 ½ teaspoons baking powder
1/8 teaspoon kosher salt
½ cup plus 1 ½ tablespoons blood orange olive oil (such as Con Olio or other brand)
2 whole eggs
Scant 1 ¼ cups Greek-style yogurt
Zest of three blood oranges (regular oranges may be substituted)
1 tablespoon vanilla extract 

Preheat oven to 350 degrees.

In a bowl, mix dry ingredients together. In another bowl, combine the oil, eggs, yogurt, sugar, and blood orange zest, whisking until well mixed. Fold the dry ingredients into the wet ones and combine well. 

Lightly oil a half sheet pan and line bottom with parchment paper, cut to fit. Then oil the upper side of the parchment paper too. Pour the cake batter into the pan and spread evenly. Bake for ten minutes, then rotate the pan 180 degrees and bake for another 10 minutes. Cake is done when a toothpick stuck in the center comes out clean (do not allow cake to brown at all). Remove from oven and cool on a rack.

Optional: To make an orange glaze, in a bowl whisk together ½ cup blood orange olive oil and ¼ cup blood orange juice. Pour or brush onto the cooled cake. Serves 8 to 10.