Preheat your oven to 350°F (175°C).
Grease and flour two 9-inch round cake pans.
In a large bowl, mix together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
In another bowl, whisk the eggs, milk, vegetable oil, and vanilla extract until well combined.
Gradually add the wet ingredients to the dry mixture, stirring until just combined.
Divide the batter evenly between the prepared pans and smooth the tops.
Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes before turning them out onto wire racks to cool completely.
Once cooled, place one layer on a serving plate and spread a layer of caramel sauce over the top.
Sprinkle half of the chopped pecans over the caramel layer.
Top with the second cake layer and repeat with caramel and pecans.
Pour the chocolate ganache over the top of the cake, allowing it to drip down the sides.
Chill the cake for at least 30 minutes to set the ganache before serving.