Preheat your oven to 350°F (175°C) and prepare three 9-inch round cake pans by greasing and flouring them.

In a large mixing bowl, whisk together the flour, granulated sugar, cocoa powder, baking powder, baking soda, and salt until well combined.

Add the buttermilk, vegetable oil, eggs, and vanilla extract to the bowl of dry ingredients and mix until smooth.

Gradually stir in the hot water until the batter is silky smooth.

Divide the batter evenly among the three prepared pans and bake for 30-35 minutes, or until a toothpick inserted comes out clean.

Let the cakes cool in their pans for 10 minutes before transferring them to a wire rack to cool completely.

In a saucepan, heat the sugar over medium heat until it melts and turns amber. Add the butter and stir until melted.

Slowly pour in the heavy cream while stirring constantly, then stir in the vanilla extract and salt before letting it cool.

In a microwave-safe bowl, combine the chocolate chips and heavy cream. Heat in 30-second intervals, stirring in between until smooth.

Place one layer of cake on a serving plate and spread a layer of caramel sauce on top.

Sprinkle half of the chopped pecans over the caramel and drizzle with chocolate ganache. Repeat with the second layer.

Place the final cake layer on top and frost the top and sides with the remaining caramel sauce and ganache. Decorate with pecan halves.

Allow the cake to chill in the fridge for at least 30 minutes before slicing.