Preheat your oven to 325°F (163°C). Grease and flour a 9x13-inch baking pan to prevent the cake from sticking.

Place the vanilla wafers in a food processor and pulse until finely crushed. Alternatively, you can place them in a zip-lock bag and crush them with a rolling pin.

In a large mixing bowl, use an electric mixer to cream the softened butter, granulated sugar, and brown sugar until light and fluffy.

Add the eggs one at a time, beating well after each addition. This ensures the eggs are well incorporated into the mixture.

Pour in the milk and vanilla extract, mixing until the batter is smooth and well combined.

In a separate bowl, combine the crushed vanilla wafers, baking powder, and salt. Gradually add this dry mixture to the wet ingredients, mixing until just combined.

Gently fold in the chopped pecans, distributing them evenly throughout the batter.

Pour the batter into the prepared baking pan. Smooth the top with a spatula. Bake in the preheated oven for 50 minutes or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan on a cooling rack for about 10 minutes. Then, transfer the cake to the rack to cool completely before serving.