Preheat the oven to 375 degrees.

In a small saucepan add the sugar and cornstarch. Stir to combine.

Whisk in the eggnog until smooth.

Bring the mixture to a low boil. Reduce the heat and cook for 2 minutes.

Stirring constantly Remove the saucepan from the heat; add in the butter and extract.

Stir until the butter is melted and smooth.

Pour the pie mixture into the pie crust.

Bake for 20-25 minutes.

In a medium bowl, add the gingersnaps, flour, sugar, oats, and cinnamon. Stir to combine.

Add your chopped butter to your mixture.

Using your hands combine the butter with the mixture.

Make sure there are no chunks of butter and its small crumbs.

Add the crumble on top of the pie and bake for another 5 minutes.

Remove from the oven and allow to cool. Enjoy!