Wash Navel orange and trim off the bottom, if necessary.
Cut into quarters. Put in cold water. Bring to boil for 30 minutes. Drain. Reserve 1/4 cup water.
Add to Vitamix and pulse until you have a texture of puree, yet with a little bit of zest showing. You may need to add a little water in bottom of blender. Set aside to cool. This can be made up to 3 days ahead and refrigerated.
Preheat oven to 350 Degrees. Keep on bake, not convection bake if oven has that mode.
You can use a hand mixer or stand mixer to make batter. Add oil and Swerve. Once mixed, add eggs and mix each one at at time for 30 seconds to fully incorporate.
Add 1 1/4 cups orange mixture to the eggs and mix well. Make sure you have about 1/4 cup reserved for the orange glaze topping.
Add vanilla extract.
In a separate bowl whisk the remaining dry ingredients. Add to the egg mixture.
Give the pan one more light spray with baking spray.
Pour batter into the prepared bundt pan. Smooth out top with offset spatula.
Bake for approximately 50 to 55 minutes. Test at 50 minutes. Internal temperature should be approximately 207 degrees F, no more than 210. Cover with foil if cake starts to brown too much, at 40 minutes.