Adjust an oven rack to the middle position and preheat the oven to 350°F [180°C]. Generously grease a 12 cup [2.8 L] tube or Bundt pan (see note). Do not use a tube pan with a removable bottom. Sprinkle in sesame seeds if desired (see note again).
In a medium bowl, whisk together the flour and baking soda.
In a medium bowl or liquid measuring cup, whisk together the sour cream and whole milk until combined.
In the bowl of a stand mixer fitted with a paddle, beat the butter on medium speed until creamy, about 1 minute. Add the dark brown and granulated sugars and salt and beat on medium speed until very light and fluffy, 4 to 6 minutes.
Scrape down the sides of the bowl and add the eggs one at a time, beating on medium speed until incorporated and stopping to scrape down the sides of the bowl after each addition. Add the toasted sesame oil and vanilla and mix on low speed to combine. Add half of the flour mixture and mix on low speed until combined. Add the sour cream mixture and mix on low speed until combined. Scrape down the sides of the bowl, add the remaining flour mixture, and mix on low speed until combined. Increase the speed to medium and beat for 15 to 20 seconds.
Pour the batter into the prepared pan and use a spatula to even out the top. Bake for 50 to 65 minutes, until a wooden skewer or toothpick inserted near the center comes out clean.
Transfer the pan to a wire rack and gently run a plastic knife (metal will scratch) around the edge of the cake to loosen it. Let cool for 10 minutes in the pan, then invert the cake onto the rack and remove the pan to finish cooling. The cake can be wrapped in plastic wrap and kept at room temperature for 2 days, or refrigerated for up to 4 days.