Preheat oven to 325 degrees F. Grease and sugar (I use granulated sugar but you can use flour) a 10x4-inch, 12 cup bundt pan (that's larger than a typical bundt pan) or a tube pan with solid vegetable shortening or Wilton Cake Release.
In the bowl of your electric mixer, cream butter and shortening at medium speed. Gradually add brown sugar, beating until light and creamy. Stop mixer and scrape sides.
Add eggs, 1 at a time, beating just until blended. Stop mixer and scrape sides with a spatula.
Add bourbon to half and half; set aside.
In a separate bowl, stir together flour, baking powder, and salt. Add flour mixture alternately with the milk mixture to the ingredients in the mixing bowl beginning and ending with flour. Beat at low speed just until blended after each addition. Stop mixer and scrape sides with a spatula.
Stir in vanilla. Pour batter into your prepared baking pan.
Bake at 325°F for 1 hour 10 to 15 minutes. A long wooden pick inserted in the center should come out clean when the cake is done. Cool in pan on wire rack 15 to 20 minutes then remove from pan to cake plate.
Cool the cake completely on a wire rack before glazing. It will take about an hour for the cake to cool completely.