Step 1

Soften the butter and let the eggs warm up. Place 14 tablespoons (1 3/4 sticks) unsalted butter in the bowl of a stand mixer fitted with the paddle attachment and let sit at room temperature until softened. (Alternatively, use a large bowl and electric hand mixer.) Place 3 large eggs on the counter while the butter softens.

Step 2

Preheat the oven and prepare the pan. Arrange a rack in the middle of the oven and heat the oven to 350°F. Coat a 10 to 15-cup bundt pan generously with butter, getting into all the nooks and crannies. Sprinkle 2 tablespoons raw sugar into the pan, coating all the sides evenly.

Step 3

Sift the dry ingredients. Place a large fine-mesh strainer or sifter over a large bowl. Add 2 1/2 cups cake flour, 1 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon kosher salt to the sifter. Sift into the bowl.

Step 4

Optional: Add the vanilla seeds to the sugar. If using a vanilla bean, place 1 1/2 cups granulated sugar in a small bowl. Split the vanilla bean, then scrape the seeds into the sugar. Use your fingers to work the seeds into the sugar.

Step 5

Beat the butter and sugar. Beat the softened butter on medium speed for 30 seconds. With the mixer still running, gradually beat in the sugar. Stop the mixer and scrape down the sides of the bowl.

Step 6

Add the vanilla extract. Add the vanilla extract: 2 teaspoons if also using vanilla seeds, or 5 teaspoons if you are not using vanilla seeds.

Step 7

Beat until very light and fluffy. Beat on high speed until light and creamy, 5 to 6 minutes. Stop the mixer and scrape down the sides of the bowl.

Step 8

Add the eggs. With the mixer on medium to high speed, gradually add the 3 eggs one at a time, waiting until each one is incorporated before beating in the next. If the batter looks curdled, just add 1 or 2 tablespoons of the flour mixture to bind it back together.

Step 9

Add the flour mixture. With the mixer on low speed, beat in the flour mixture.

Step 10

Add the sour cream, orange zest, and orange juice. Add 3/4 cup sour cream, 1 tablespoon finely grated orange zest, and 1 tablespoon orange juice, and beat until just combined. Stop the mixer and scrape down the sides of the bowl.

Step 11

Transfer the batter to the bundt pan. Transfer the batter into the prepared bundt pan and smooth the top.

Step 12

Bake about 45 minutes. Bake until a skewer inserted into the cake comes out clean or with only a few moist crumbs, the cake bounces back when lightly pressed, and the top is golden-brown, about 45 minutes.

Step 13

Cool the cake 10 minutes. Place the pan on a wire rack and let the cake cool for 10 minutes.

Step 14

Flip the cake out of the pan while still warm. Use a table knife to gently push the cake away from the sides of the pan. Place the rack over the pan, then flip both over in one motion. Remove the pan from the cake. Let the cake cool completely. Meanwhile, let 1 tablespoon unsalted butter sit at room temperature to soften if making the glaze.

Step 15

Make the glaze (optional). Sift 1 cup powdered sugar into a small bowl. Make a well in the center of the sugar and add the 1 tablespoon softened unsalted butter. Pour 2 tablespoons boiling water onto the butter to melt it. Stir together until smooth.

Step 16

Glaze the cake. Pour the glaze over the cake, then let sit until set before slicing the cake and serving.