Heat oven to 325 degrees F. Grease a 10-inch bundt pan with baking spray.
In the bowl of a stand mixer, beat the butter until light and creamy about 2 minutes on medium speed. With the mixer running, slowly add in the granulated sugar. Cream butter and sugar until light and fluffy, about 8 minutes on medium speed. Add eggs, one at a time and mixing in between until combined, scraping down bowl as needed.
Reduce mixer speed to low and add in the slat and the flour, one cup at a time, mixing until just combined. Using a rubber spatula, fold in the champagne into the mixture. Use the vegetable oil to grease the pan
Pour the batter into the prepared pan and bake until a cake tester inserted into the center comes out clean, about 1.5 hours (be sure to keep an eye on it as it could bake faster depending on the size of your bundt pan).
Let cake cool in pan for at least 10 minutes before transferring to a cooling rack. Let cool completely.
To make icing whisk the champagne with the powdered sugar in a small bowl. Drizzle glaze over cooled cake.