Preheat oven to 350°F (175°C) and grease a 9x13 inch baking pan or line with parchment paper.

Mix graham cracker crumbs and melted butter in a small bowl until combined; press firmly into the bottom of the prepared pan.

In a medium bowl, whisk together the pumpkin puree, pumpkin pie spice, and sweetened condensed milk until the mixture is homogeneous.

Pour the pumpkin mixture evenly over the graham cracker crust layer.

Distribute the chocolate chips, chopped pecans, and shredded coconut in even layers over the pumpkin mixture.

Press the toppings down lightly with a spatula to ensure they are partially submerged in the liquid base.

Bake for 25 to 30 minutes until the coconut is toasted and the edges are bubbling.

Remove from oven and allow to cool completely at room temperature for at least 2 hours before slicing into squares.