In a mixing bowl, combine crushed vanilla wafers, melted unsalted butter, and finely chopped pecans. Stir until the mixture resembles wet sand.

Press this mixture firmly into a greased 9x13 inch baking pan, creating an even layer.

Bake at 350°F (175°C) for 10-15 minutes until edges turn a rich mahogany color. Allow to cool completely.

In a clean bowl, beat the softened cream cheese and powdered sugar with a hand mixer until smooth and fluffy, about 2-3 minutes.

Fold in half of the thawed whipped topping carefully to maintain volume, then spread over cooled pecan crust.

Whisk together instant chocolate pudding mix and cold whole milk until thick and smooth, about 2-3 minutes.

Pour the pudding over the cream cheese layer and spread it evenly for a smooth finish.

Spread remaining whipped topping over the chocolate layer and garnish with chocolate shavings or curls.

Cover with plastic wrap and refrigerate for at least 4 hours before serving.