To prepare the cake:
- Preheat the oven to 350 degrees. In the bowl of a stand mixer, cream the Kerrygold unsalted butter, sugar, and brown sugar together on medium speed for 4 minutes.
- Scrape the sides of the bowl and add the eggs one at a time. Scrape the sides of the bowl and stir in any unincorporated egg. In a separate bowl combine the buttermilk, bourbon, and vanilla extract.
- In another bowl, stir together the flour, baking powder, soda, and salt. Add half of the dry ingredients to the butter mixture and stir just until barely combined on low speed.
- Add half of the liquid ingredients and stir to combine.
- Repeat this process to incorporate the remaining dry and wet ingredients.
- Fold the batter together using a rubber spatula to ensure everything is well incorporated.
- Lightly grease and flour a bundt pan and spoon the batter into the pan.
- Bake in the preheated oven until the cake has risen and a toothpick inserted comes out clean, about 45- 50 minutes.
- Allow to cool for 20 minutes in the pan, then invert the cake on to a cooling rack to cool completely.
To prepare the glaze:
- Whisk together the powdered sugar, bourbon, and ¼ cup of heavy whipping cream.
- Add additional cream 1 teaspoon at a time until your glaze is the desired consistency.
- Add additional powdered sugar to thicken as needed.
- Spoon the glaze over top of the cake and enjoy!