For The Cake: Preheat oven to 350 degrees. Grease a 12-cup Bundt and dust with flour. Combine the flour, baking soda, espresso powder, and salt in a medium mixing bowl.
Combine the butter, chocolate, and espresso in a medium saucepan. Heat over medium, stirring until the butter and chocolate are melted. Remove from the heat and stir in the granulated sugar and bourbon.
Place the eggs, sour cream and vanilla in a large mixing bowl and beat with an electric mixer on low to break up the eggs. Beat in the chocolate mixture. Add the flour mixture and stir until just combined. Stir in the chocolate chips and pecans (if using).
Scrape the batter into the prepared pan and smooth the top with a spatula. Bake until a toothpick inserted into the center of the cake comes out clean, about 45 minutes. Let the cake cool in the pan for 5 minutes and then invert it onto a wire rack to cool completely.
For The Glaze: Stir the butter, brown sugar, and espresso powder together in a small saucepan over medium heat until the butter is melted. Whisk in the cream and bring to a simmer. Cook for 1 minute, remove from the heat, and whisk in the powdered sugar until smooth. Mix in the bourbon. Let cool for 10 minutes.
Place the cake, still on the wire rack, over a baking sheet (or parchment paper). Slowly drizzle the glaze over the cake, letting it run down the sides of the cake and covering as much of the cake as possible. Let stand until the glaze is set, about 1/2 an hour. Slice and serve.
Store uneaten cake on a cake keeper or wrap in plastic and store at room temperature for up to 3 days.