Preheat oven to 325.
Butter and flour a 10-cup Bundt pan and grease with nonstick spray.
Combine bourbon and vanilla in a small bowl, stir and set aside.
In a medium-sized bowl whisk together the flour, baking powder, and salt; set aside.
In a large mixing bowl beat together the butter and both sugars until creamy.
Add in the eggs, one by one, beating until well blended.
Pour in the bourbon mixture and continue to mix until incorporated.
Slowly add in the flour mixture.
Pour in the milk and continue to mix until well incorporated and smooth.
Transfer the batter to the prepared bundt pan; smooth the top and bake for 55 minutes, or until a toothpick inserted in the center comes out clean.
Cool in pan for 10 minutes, then invert onto a cooling rack.
Cool completely.
Dust with powdered sugar.