Make the cake:
Position a rack in the center of the oven and heat the oven to 350°F. Butter a 10-inch (12-cup) Bundt pan and dust it with the breadcrumbs, shaking out and discarding the excess crumbs.
Sift together the flour, baking powder, and baking soda into a medium bowl. Add the salt and mix with a rubber spatula.
In a stand mixer fitted with the paddle attachment, beat the butter on medium speed, gradually adding the brown sugar until the mixture is light and fluffy, about 3 minutes. Add the eggs one at a time, mixing just enough to incorporate and pausing to scrape the bowl once or twice. Add the vanilla and mix until just combined.
In a measuring cup, combine the buttermilk with the bourbon. With the mixer running on low speed, alternate adding the flour mixture and the buttermilk mixture in five additions, beginning and ending with the dry ingredients, stopping occasionally to scrape the bowl. Mix until just combined. Add the toasted pecan pieces and mix until the nuts are just incorporated.
Pour the batter into the prepared pan and smooth the top with a spatula. Bake until the cake is golden brown and a cake tester or skewer comes out clean, 65 to 70 minutes. Transfer the cake to a rack and cool in the pan for 15 minutes.
Make the glaze:
Combine the sugar and bourbon in a small saucepan or skillet. Cook over medium-low heat until the mixture comes to a simmer and the sugar dissolves, 3 to 5 minutes. Turn the cake out of the pan onto a cooling rack. With a pastry brush, brush the warm glaze over the entire surface of the cake. Allow to cool completely.
This cake can be made up to 2 days ahead.