Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking dish or line it with parchment paper for easy removal.

Mix together the melted butter and brown sugar in a large bowl until well combined.

Add the egg, pumpkin puree, and vanilla extract. Stir until smooth.

In a separate bowl, whisk together the flour, pumpkin pie spice, cinnamon, baking soda, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Fold in the white chocolate chips until evenly distributed throughout the batter.

Pour the batter into the prepared baking dish, spreading it out evenly with a spatula.

Sprinkle chopped pecans evenly over the top of the batter, if desired.

Bake in the preheated oven for 30-35 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out clean or with a few moist crumbs.

Allow the blondies to cool in the pan for about 15 minutes before cutting them into squares. Enjoy warm or at room temperature!