Preheat the oven to 350°F (175°C) and grease two round baking pans with vegetable oil, dusting with flour.

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

In another bowl, beat sugar with vegetable oil until light and fluffy. Add eggs one at a time, then mix in milk and vanilla extract.

Gently fold the dry ingredients into the wet mixture until just combined.

Divide the batter between the prepared pans and bake for 30-35 minutes, checking with a toothpick.

Let the cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.

Prepare instant chocolate pudding according to package instructions using cold milk and refrigerate until thickened.

Heat heavy cream over medium heat until simmering, then pour over chocolate chips in a bowl and stir until smooth.

Place one cake layer on a serving plate and spread chilled pudding over the top.

Carefully place the second cake layer on top and drizzle with the ganache.

Allow the ganache to set for a few minutes before slicing and serving.