Step 1

Preheat the oven to 425 degrees with the rack in the middle.

Step 2

Transfer the dulce de leche to a microwave-safe bowl and microwave on HIGH for 45 seconds to 1 minute. It should be just warm, not hot, and soft enough to be easily incorporated into the filling. Let cool slightly.

Step 3

In a small bowl, whisk together the cinnamon, cardamom, ginger, nutmeg and salt. In a large bowl, whisk the eggs until combined. Whisk in the pumpkin and spice mixture. Gradually whisk in the evaporated milk. Whisk in the dulce de leche a little at a time, fully incorporating after each addition. Pour the filling into the pie shell.

Step 4

Bake for 15 minutes. Reduce the temperature to 350 degrees and bake for 30 to 40 minutes, or until a knife inserted near center comes out clean. The pie will be mostly set but still jiggle a bit in the center.

Step 5

Cool on a wire rack for 2 hours. Top with the whipped cream and dust with cinnamon, if desired. Serve, or refrigerate until needed.