Step 1

Preheat the oven to 350°F. Generously butter and flour a 12 cup Bundt pan or using baking spray.

Step 2

Whisk together the eggs, yolks, vanilla and 1/2 cup of the buttermilk, set aside.

Step 3

Sift the flour, sugar, baking powder and salt into a mixer bowl. Mix on low speed to combine the dry ingredients. Toss the chunks of butter into the flour mixture.

Step 4

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.

Step 5

Add the eggs in 3 batches, scraping the bowl between each addition. Pour the batter into the prepared pan.

Step 6

Bake until the cake springs back when lightly pressed or a toothpick inserted into the center comes out clean, about 45 minutes.

Step 7

Cool for 5 minutes in the pan. Invert the cake onto a cooling rack set over a clean sheet pan.

Step 8

Combine the sugar, vanilla and buttermilk and whisk until smooth.

Step 9

Pour the glaze over the still slightly warm cake. You can scoop up the glaze from the sheet pan and use it to fill in any gaps in the glaze.

Step 10

Cool completely and allow the glaze to set. Transfer to a serving plate.