Preheat an oven to 350 F. Grease and line a 9x13 baking pan with parchment paper and set aside.
Melt the chocolate, butter, and oil. In a small saucepan, combine the chopped chocolate, butter, and neutral oil. Melt it over low heat until the chocolate is completely melted and smooth. Remove from the heat and whisk in the cocoa powder until smooth and let it cool slightly.
Mix the dry ingredients. In a small bowl, whisk together the flour, baking soda, and salt and set aside.
Whisk the eggs and sugar. In a large mixing bowl, whisk together the sugar and eggs for 2-3 minutes, until frothy. Then, whisk in the sour cream and vanilla until smooth.
Mix in the chocolate. Whisk in the cooled chocolate mixture into the eggs until smooth. Only add a little at a time while whisking, until the chocolate is totally incorporated.
Fold in the dry ingredients. Switch to a rubber spatula and fold in the flour mixture until totally smooth and no streaks of flour remain. Switch back to a whisk and whisk in the hot coffee and whiskey until the batter is smooth, with no lumps.
Bake. Pour the batter into the prepared pan and bake for 30-35 minutes, or until a cake tester comes out clean. Let the cake cool completely before removing from the pan.
Make the frosting. In a mixing bowl, use a hand mixture to beat the butter, sugar, and cocoa powder together until smooth and fluffy. Beat in the vanilla, salt, and Bailey's until smooth and the frosting is fluffy. Spread over the cooled cake, cut into pieces, and serve.