Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish.
In a mixing bowl, combine flour, melted butter, and sugar for the crust. Press into the bottom of the prepared baking dish.
Bake crust for 15 minutes. Remove from oven and set aside.
In another bowl, whisk together pumpkin puree, eggs, evaporated milk, sugar, cinnamon, ginger, and cloves. Pour over the baked crust.
In a small bowl, mix chopped pecans, brown sugar, and melted butter. Sprinkle over the pumpkin filling.
Bake for 45 minutes or until set. Let cool before slicing into bars.