Instructions:

1. Preheat oven to 325°.  An oven thermometer is highly recommended, since many ovens run hot or cold.
2. Place flour, salt, baking soda and cardamom (if using) in a medium-sized bowl.  Sift dry ingredients into a large bowl and set aside.
3. Add granulated sugar, eggs, olive oil, vanilla extract, blood orange zest, blood orange juice, and sour cream in a medium bowl. 
4. Stir wet mixture with a whisk until it is completely combined.  The oil and egg will be the last things to combine.  The mixture should be completely and consistently mixed before moving onto the next step.
5. Add the wet mixture to the dry mixture.  Use a rubber spatula to get all of the wet mixture into the bowl with the dry mixture.
6. Stir the batter with a whisk until only a few lumps remain.  The orange zest will make the batter appear lumpy as well.  Don’t be fooled by this!
7. Add the batter to a prepared 9” x 5” or 8.5” x 4.5” loaf pan.  Place the loaf pan atop a parchment-lined baking sheet.  If making “candied” oranges, place the oranges directly on the parchment-lined baking sheet, next to the cake pan.
8. Bake in a 325°F oven for 60-70 minutes, or until an instant read thermometer reads 212°F-215°F.  Alternatively, your cake is done when a fingerprint indent springs back and a toothpick in the center comes out completely clean.
9. Remove the cake and orange slices from the oven once the cake is complete.
10. Place the cake pan on top of a cooling rack for ten minutes.  Then, remove the cake from the cake pan and allow to cool completely before slicing.  See below for simple syrup and “candied orange” instructions (if using).
11. If you are not using simple syrup, this cake can be sliced about an hour after it comes out of the oven and served warm.

If Using Simple Syrup:

1. After removing the cake from the oven, make the simple syrup.  Begin by adding sugar, water, and salt to a small saucepan.  Bring to a boil.
2. Reduce mixture to a simmer and cook until the sugar is completely dissolved.  
3. Turn off the heat and add the orange juice.  Stir until dissolved.
4. Use a pastry brush to brush the simple syrup over the warm cake (and orange slices, if using), immediately after removing the cake from the cake pan.
5. Allow the cake to cool completely before eating.