2 sticks unsalted butter, softened (plus more for greasing the pan)
2 cups granulated sugar (plus more for dusting the pan)
5 ounces unsweetened chocolate, chopped
1/4 cup instant espresso powder
2 tablespoons unsweetened cocoa powder
1 cup bourbon or whiskey
1/2 teaspoon kosher salt
2 large eggs
1 tablespoons vanilla extract
1 teaspoon baking soda
2 cups all-purpose flour
Grease a 10-cup bundt pan with butter and then dust with granulated sugar. Preheat oven to 325 degrees. Melt the chocolate and let cool.
Put the espresso and cocoa powders in a 2-cup measuring cup. Add enough boiling water to come up to the 1-cup measuring line. Whisk together until powders dissolve. Add the whiskey and salt. Let cool a bit.
Using an electric mixer, beat the butter and sugar until light and fluffy. Beat in the eggs, one at a time, beating well between each addition, scraping the bowl with a spatula, as needed. Beat in the vanilla extract, baking soda, and melted chocolate, again scraping down the sides of the bowl as needed. On low speed beat in 1/3 a cup of the whiskey mixture then half of the flour, then half of what is left of the whiskey mixture, the rest of the flour, and then ending with the last bit of whiskey mixture, making sure you allow each addition to totally mix in, but without overbeating the cake. Pour the cake into prepared pan and smooth the top. Bake for about 1 hour (might need a few minutes more or less), until toothpick comes out mostly clean.