Preheat your oven to 325 degrees F. Spray a 10-12 cup bundt pan with nonstick cooking spray, sprinkle turbinado sugar or flour around the sides.
In a medium pot, bring water to a boil. Add in 2 cups of the oats, stir, and remove the pot from the heat. Cover the pot and allow the oats to soak for 20 minutes, until all the water is absorbed. Let the oatmeal cool completely before adding it to the cake batter.
In a medium sized mixing bowl, combine the cake flour, remaining 1/2 cup oats, baking soda, cinnamon, and salt. Stir to combine. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugars together on medium speed for 2 minutes until light and fluffy. Add in the vanilla and the eggs and mix until combined, scraping the sides of the bowl as necessary. Turn mixer to medium-high and beat the mixture for about 2 to 3 minutes, until smooth in texture and slightly lighter in color.
Turn the mixer to low and add in the cooled cooked oats, followed by the flour mixture, mixing until just combined.
Pour the cake batter into the prepared bundt pan and bake for 50 to 60 minutes, until a toothpick inserted in the center of the cake comes out with a few moist crumbs on it.
Allow the cake to cool in the bundt pan completely before inverting it onto a cake plate for serving.