Preheat the oven to 350 degrees F. Generously grease and flour a bundt pan.
In the bowl of a stand mixer, beat eggs and sugar at high speed (speed 6 on my Kitchen-Aid) for 3 minutes or until thick and pale. Add oil, melted butter, and vanilla, beating at a low speed until just combined. Add the sweet potato puree, beating until just combined and stopping to scrape down the sides of the bowl.
In a separate bowl, add flour, cinnamon, nutmeg, baking powder, baking soda, and kosher salt. Whisk to combine.
In a measuring cup, whisk together the bourbon and buttermilk.
Gradually add the flour mixture to the egg mixture, alternating with the buttermilk mixture. Beat at a low speed after each addition until just combined.
Pour the batter into the prepared bundt pan. Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean. Cool in pan on a wire rack for 30 minutes. Remove from pan and allow to cool fully on the wire rack.
Glaze: While the cake is baking, bring brown sugar, butter, and maple syrup to a boil in a small saucepan over medium heat. Boil for 2 minutes, then add the pecans. Remove from heat and stir in the bourbon.
Drizzle the glaze slowly over the warm bundt cake, allowing it to soak into the cake.
Recipe by The Messy Baker Blog at http://themessybakerblog.com/2012/12/01/sweet-potato-bourbon-bundt-cake-bundtamonth/