Step 1: Prepare the Dark Chocolate Cake

1. Preheat your oven to 350°F (175°C). Grease and flour an 8-inch round cake pan.
2. In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
3. In a large bowl, beat the softened butter and sugar together until light and fluffy, about 3–4 minutes.
4. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
5. Gradually add the dry ingredients to the butter mixture, alternating with the buttermilk and whiskey. Start and end with the dry ingredients, mixing just until combined.
6. Pour the batter into the prepared cake pan and smooth the top. Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

Step 2: Prepare the Whiskey Ganache

1. In a small saucepan over medium heat, bring the heavy cream to a simmer. Remove from heat.
2. Add the dark chocolate chips to the hot cream and let sit for 2 minutes. Stir until the chocolate is melted and smooth.
3. Stir in the whiskey until fully combined. Let the ganache cool slightly until pourable.

Step 3: Assemble the Cake

1. Once the cake is completely cool, place it on a serving plate. Pour the whiskey ganache over the top, allowing it to drip down the sides.
2. For a firmer ganache, refrigerate the cake for 30 minutes to set.
3. Optionally, garnish with chocolate shavings or a sprinkle of sea salt.

Step 4: Serve

1. Slice the cake and serve, optionally with vanilla ice cream or whipped cream.