For the crust

1. In a small pot on the stove over medium-high heat, brown your butter. It’ll brown in about 5 minutes, so monitor closely to avoid burning. It’ll begin to crackle, turn amber in color, and have a nutty aroma when done.
2. In a food processor or blender, grind approximately 30 ginger snaps with your salt until they have a very fine texture, like sand. 
3. With a spatula or spoon, combine browned butter with ginger snap crumbs in a small mixing bowl until everything is the consistency of wet sand.
4. Let crust cool in bowl as you make the filling and topping.

For the topping and filling 

1. In a very cold (chill for 10-15 minutes prior to using), clean mixing bowl, whip your heavy cream (with rum extract if using) until stiff peaks form. Start on a low setting and gradually increase, taking care to avoid over mixing. Once done, gently scoop whipped cream out of mixing bowl and set aside in another container in the refrigerator.
2. Back in your mixing bowl, whip Greek yogurt on medium speed for about 30 seconds, until creamy. Stop mixer and pour in 1 can of sweetened condensed milk and eggnog. Mix until they’re combined, 30-45 more seconds on medium speed. 
3. Using a spatula, gently fold your whipped topping from the refrigerator into your mixing bowl. 
4. Set out your silicone cupcake liners, and distribute your eggnog pie amongst the dozen of them. You’ll pour about ⅓ cup of liquid into each liner, leaving some room at the top where your crust will go.
5. Similarly, distribute your ginger snap crumbs amongst the pies. 
6. Place in airtight container(s) in freezer for a few hours until firm, ideally overnight. 
7. Before removing mini pies from the freezer for serving, whip heavy cream and sugar together to make homemade whipped cream. Put into a piping bag fitted with a cake decorating tip of your choice. 
8. Bring pies out of the freezer, and carefully peel away the silicone liners from them. Place them on your serving dish, and pipe whipped cream atop pies. Dust with nutmeg if you'd like. Serve and enjoy!