• Preheat the oven to 350 °F. Butter and flour a 12 cup Bundt pan.

Make the batter

• Whisk together 2 large eggs, 2 large yolks, 2 teaspoons vanilla extract and 1/2 of the buttermilk, set aside.
• Sift 11 ¼ oz cake flour, 11 oz granulated sugar, 1 tablespoon baking powder and ½ teaspoon table salt into a mixer bowl. Mix on low speed to combine the dry ingredients. Toss 6 oz unsalted butter into the flour mixture and mix until the butter begins to break down.
• With the mixer running on low, add the reserved 1/2 cup of buttermilk. Increase the speed to medium. Mix on medium high for 2 minutes to aerate the batter. Scrape the bowl.
• Add the eggs in 3 batches, scraping the bowl between each addition. Pour the batter into the prepared pan.
• Bake until the cake springs back when lightly pressed and a toothpick inserted into the center comes out clean, about 45 minutes.
• Cool for 10 minutes in the pan. Invert the cake onto a cooling rack set over a clean sheet pan.

Make the Glaze

• Combine 8 oz confectioner sugar, 1 teaspoon vanilla and 2 oz buttermilk and whisk until smooth.
• Pour the glaze over the still slightly warm cake (see note). You can scoop up the glaze from the sheet pan and use it to fill in any gaps in the glaze or just leave the glaze with the drip effect.
• Cool completely and allow the glaze to set. Transfer to a serving plate.