In a bowl, whisk together the milk and instant chocolate pudding until it begins to thicken. Set aside.
In a separate bowl, add the heavy whipping cream, powdered sugar, vanilla, and softened cream cheese. Beat until thick, smooth, and fluffy, forming soft peaks.
In a deep 9x13-inch baking dish, spread a thin layer of chocolate pudding on the bottom.
Add a layer of chocolate graham crackers, breaking or trimming some pieces so the entire bottom is covered.
Spread half of the remaining chocolate pudding over the graham crackers, then top with half of the whipped cream cheese mixture.
Add another layer of chocolate graham crackers.
Spread the remaining chocolate pudding, then finish with the rest of the whipped cream cheese mixture.
Drizzle chocolate ganache or chocolate syrup over the top and sprinkle with mini chocolate chips.
Cover and refrigerate for 4 to 6 hours, but overnight is best so the graham crackers soften and the flavors come together.