Gingersnap Crust

1. Preheat oven to 325ºF.
2. Mix the gingersnap crumbs and melted butter together until thoroughly combined. Divide mixture evenly between four 4 1/2" tartlet pans and press into bottom and sides, keeping thickness even throughout.
3. Place tartlet pans on a baking sheet and scatter any remaining crust crumbs onto baking sheet. Bake in preheated oven for 10-13 minutes, until crust has puffed up slightly and no longer looks wet. Allow to cool to room temperature before prepping filling.

Boozy Chocolate Filling

1. In a small bowl, whisk together the sugar, flour, espresso powder, and salt. Set aside.
2. In a small saucepan, bring the milk and cream to a simmer.
3. Place the egg yolks in a medium bowl and whisk lightly. While whisking, slowly stream the milk mixture into the egg yolks about 1/4 cup at a time, continuing until all is added and evenly combined. Add the flour mixture and whisk in until smooth.
4. Return mixture to saucepan. Cook over medium-low heat, stirring constantly, until custard thickens and just begins to come to a boil. Remove from heat immediately and whisk in chocolate and butter until smooth. Add rum and whisk until smooth.
5. Divide filling evenly between tartlets and refrigerate until cool and set, at least an hour. Sprinkle any remaining baked crust crumbs over filling before topping with meringue.

Rum-Spiked Spiced Meringue

1. When ready to serve tartlets, prepare the meringue.
2. In the bowl of a stand mixer fitted with the wire whip attachment, combine the egg whites and cream of tartar and beat on medium-high until soft peaks form. Add 1 tablespoon sugar and beat in briefly to incorporate.
3. In a small saucepan, whisk together remaining 3 1/2 ounces (1/2 cup) granulated sugar with the water and corn syrup. Set over medium heat and stir constantly until sugar has dissolved. Bring to a boil and maintain, without stirring, until syrup reaches 230ºF as measured by an instant-read thermometer.
4. With mixer on low speed, slow pour sugar syrup along the side of the bowl into egg whites. Once all has been added, increase speed to medium-high and continue to beat. Once meringue is fluffy, beat in cinnamon, ginger, and all spice. Continue to beat until both the bowl and the meringue are no longer warm and meringue is fairly stiff and glossy. Towards the end of this time, beat in the rum, slowly streaming in 1 tablespoon at a time.
5. Dollop meringue evenly between tartlets, using an offset spatula to spread over filling and form peaks and swirls. Carefully toast with a kitchen torch. Serve immediately.