Preheat oven to 350 degrees. Butter and lightly flour a standard bundt cake pan. Set aside.
In a medium bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.
In a large bowl, cream together the softened butter and sugars. Add in the eggs, bananas, bourbon, and vanilla and mix until well combined. Beat in the flour mixture in three additions, alternating with the sour cream. Fold in the chopped pecans. Spread batter into prepared bundt pan.
Bake on center rack in oven until a toothpick comes out clean, 45-50 minutes. Cool on a wire baking rack for 10 minutes before removing from pan and then let cool completely.
To make the Bourbon Butter Glaze, melt butter in a small saucepan over medium heat. Whisk in the powdered sugar, bourbon, and vanilla until smooth and well combined. Simmer for 2-3 minutes to cook off some of the alcohol. Note that the glaze will appear slighly grainy. Cool completely before drizzling over cooled cake. Sprinkle with chopped pecans.
Notes
This tasty recipe can be made ahead and stored in an airtight container in the refrigerator for up to a week. Also freezes great!