Preheat your oven to 375°F and prepare a 12-inch cast iron skillet or a medium casserole dish by buttering it generously.
In a large mixing bowl, whisk together the pumpkin puree, granulated sugar, eggs, pumpkin pie spice, salt, and vanilla extract until well combined. Slowly add in the heavy cream, whisking until smooth before pouring this mixture into your prepared skillet.
In another bowl, combine flour, sugar, cinnamon, and salt using a whisk. Pour in melted butter and mix with a fork until you achieve a crumbly texture.
Evenly distribute the cinnamon streusel over the top of the pumpkin filling in your skillet.
Place your assembled Pumpkin Crisp in the oven and bake for about 40 to 45 minutes or until the filling is set and the topping turns golden brown.
Allow it to cool for about 10 minutes before serving warm topped with ice cream or whipped cream.