Step 1: Preheat and Prepare the Pan

1. Preheat your oven to 350°F (175°C).
2. Generously grease a 10-cup Bundt pan with butter or non-stick baking spray. Lightly dust the pan with flour, tapping out the excess to ensure easy release.

Step 2: Mix the Dry Ingredients

1. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

Step 3: Cream Butter and Sugar

1. In a large mixing bowl, using a stand or hand mixer, beat the unsalted butter on medium speed until creamy and smooth, about 2 minutes.
2. Gradually add the granulated sugar, beating until light and fluffy, about 3-4 minutes. Scrape down the sides of the bowl as needed.

Step 4: Add Eggs and Vanilla

1. Add the eggs one at a time, beating well after each addition.
2. Mix in the pure vanilla extract until fully combined.

Step 5: Alternate Wet and Dry Ingredients

1. With the mixer on low speed, add the dry ingredients in three parts, alternating with the whole milk and sour cream. Begin and end with the flour mixture.
2. Mix until just combined, being careful not to overmix to keep the cake tender.

Step 6: Bake the Cake

1. Pour the batter evenly into the prepared Bundt pan, smoothing the top with a spatula.
2. Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
3. Let the cake cool in the pan for 15 minutes before inverting it onto a wire rack to cool completely.

Step 7: Make the Vanilla Bean Glaze

1. In a medium bowl, whisk together the powdered sugar, heavy cream, vanilla bean seeds (or paste), pure vanilla extract, and a pinch of salt.
2. If the glaze is too thick, add an additional teaspoon of heavy cream until it reaches a pourable consistency.

Step 8: Glaze the Cake

1. Once the cake is completely cooled, drizzle the vanilla bean glaze over the top, allowing it to cascade down the sides.
2. Let the glaze set for about 15 minutes before serving.