Preheat oven to 350 F. Line an 8×4-inch loaf pan with parchment paper and then spray with non-stick cooking spray. Line a baking sheet with parchment paper and place loaf pan on it. Set aside. For the chocolate syrup, place the oil and cocoa in a medium bowl and whisk together to blend. Set aside. Using a food processor, blend the sugar and the butter to make a fluffy and well-blended mixture (1-2 minutes). Add the vanilla and eggs and blend to combine (15-20 seconds). Stop the machine and add the flour, baking powder, and salt. Blend well (about 10 seconds) and then add the orange juice and process to blend (20-30 seconds), stopping the machine once or twice to scrape down the sides of the bowl. Remove one-third of the batter and place it in the bowl with the chocolate syrup. Whisk to blend. Spoon half the remaining batter into prepared pan. Top this with chocolate batter and then the last of the original batter. Swirl a bit with a butter knife. Place the pan on a baking sheet and bake for 25 minutes and then reduce the temperature to 325 F and bake another 20-35 minutes until cake is just beginning to color on top and springs back when lightly touched (total baking time is 45-55 minutes). Cool very well and then gently unmold onto a serving platter. Cool very well before serving. You may also simply dust with cocoa or powdered sugar.