Grease a 9 x 13-inch baking dish. In a food processor, combine graham crackers, pecans, brown sugar, and melted unsalted butter. Pulse until wet sand consistency. Press into the bottom of the prepared dish.

Place baking dish in the freezer for 15-20 minutes to firm up the crust.

In a mixing bowl, beat softened cream cheese, powdered sugar, and vanilla extract with an electric mixer until smooth and creamy, about 2-3 minutes.

Gently fold in half of the whipped topping using a spatula, being careful not to deflate the mixture.

Spread the cream cheese mixture evenly over the chilled crust, then spoon blueberry pie filling on top and spread gently to avoid mixing.

Layer the remaining whipped topping over the blueberry filling, smoothing it out with a spatula.

Cover with plastic wrap and refrigerate for at least 6 hours or overnight before serving.

Garnish with chopped pecans if desired, cut into squares, and serve chilled.