For the crust: In a food processor, crush the gingersnap cookies. Blend the brown sugar, cinnamon and butter with the cookie crumbs.
Press the cookie crust onto the base and sides of a 9 in pie pan. Let it chill in the fridge.
For the filling: Whisk the eggs and sugar together. Then mix in the pumpkin and milk. Lastly, add in the spices.
Preheat the oven to 375ºF.
Pour the filling into the prepared crust. Bake for 45 min until set. A toothpick test should come out clean but the pie may still look a little wobbly.
Cool the pie to room temperature.
To make the caramel: Melt the sugar on medium heat for about 5 minutes. Stir often to make sure it doesn’t burn. It should turn a deep golden color when ready to be removed from heat.
Mix in the butter and continue to stir as the bubbles die down.
Place the pot back on the stove and mix in the cream and let it cook till barely simmers. Cool to let it thicken but before it reaches room temperature.
Pour the caramel on top of the pumpkin pie and use a spoon to spread it out as necessary. Let the pie completely hill to room temperature before serving.
Notes
It is possible to crush the ginger snap cookies by hand. For the most effective manual method, use a glass or similar object and use the bottom to crush cookies in a bowl with a flat bottom.