Place cognac in a saucepan and flame. Set aside to bring to room temperature before using.

Preheat oven to 400 degrees.

In large mixing bowl, whisk together for one minute egg yolks, heavy cream, cooled cognac, vanilla, 1/2 cup of sugar, and pumpkin puree. Pour through a mesh strainer into a large pitcher and set aside.

Lightly brush eight ramekins with melted butter. Place ramekins in a pan filled with water halfway up the side of the ramekin. Fill ramekin halfway with batter. Cover pan with foil and bake for 45 minutes. Uncover pan and refrigerate crème brûlée for at least eight hours, or overnight.

Lightly dust the ramekins with remaining two tablespoons of sugar and set on a broiler pan. Broil two minutes or until bubbly.