• Preheat oven to 350°F. Generously grease a Bundt pan; set aside.
• Beat granulated sugar and butter in the bowl of a stand mixer fitted with the paddle attachment on medium-speed until combined and creamy; about 2 minutes. Add in eggs, one at a time, beating well after each addition. Reduce speed to medium-low and add in buttermilk and vanilla; mix until well combined. Add in the flour, baking powder and salt; beat just until smooth.
• Pour batter into prepared pan. Bake for 35-45 minutes or until a toothpick inserted into the center comes out clean, or with just a few crumbs attached. Carefully loosen the cake from pan using a butter knife, then turn it out onto a wire rack to cool completely.
• In the meantime, make your icing!
• In a medium-size bowl combine the confectioners' sugar, buttermilk, and vanilla extract; whisk completely smooth. If the glaze is too thick, add more buttermilk, one tablespoon at a time; if the glaze is too thin, add more confectioners' sugar, 2 tablespoons at a time. You're looking for the glaze to be thick enough to hold it's shape, but thin enough to pour.

Decorate:

• Simply pour the glaze over top the cooled cake and add sprinkles (if desired).