Preheat the oven to 350°F.

In a large bowl, cream together 1 cup of granulated sugar and 6 tablespoons of softened butter.

Add 1 egg, 1 egg yolk, and ½ teaspoon of vanilla extract, mixing until combined.

Mix in ½ cup of buttermilk.

In a separate bowl, sift together ¾ cup + 2 tablespoons of all-purpose flour, ¼ cup + 2 tablespoons of Dutch-process cocoa powder, ¾ teaspoon of baking powder, ⅛ teaspoon of baking soda, and ¼ teaspoon of salt.

Gradually add the dry ingredients to the wet ingredients, mixing until well combined.

Stir in ¼ cup of hot coffee.

Line a cupcake pan with cupcake liners and fill each cup ¾ full. Bake for 18-21 minutes, or until a toothpick inserted into the center comes out clean.

Let the cupcakes cool in the pan for 5 minutes, then transfer them to a cooling rack to cool completely.

Add 10 graham cracker sheets to a food processor and pulse until finely ground.

Add ¼ cup of powdered sugar and pulse to combine.

Pour in 3 tablespoons of melted, slightly cooled butter and mix until incorporated.

Add ¼ cup of cream and pulse until smooth and fully combined.

In a stand mixer bowl, add 6 room-temperature egg whites and 1 teaspoon of cream of tartar. Whisk until soft peaks form.

Meanwhile, heat 1 ½ cups of sugar and ¾ cup of water in a saucepan until it reaches 240°F on a candy thermometer.

Slowly pour the hot sugar syrup into the egg whites with the mixer on medium-low speed.

Increase the mixer speed to high, whipping until very firm peaks form, about 10 minutes.

Add 1 tablespoon of vanilla bean paste and mix on high speed to ensure the consistency is still firm. If the meringue is still warm, continue whipping until it reaches room temperature.

Once the cupcakes are cooled, scoop a small amount out of the center of each to make room for the filling.

Fill a piping bag fitted with a large open tip with the cookie butter and pipe it into the center of each cupcake.

Fill another piping bag fitted with a decorative tip with the meringue and pipe a generous amount over each cupcake.

Use a kitchen torch to toast the meringue until golden brown.

Serve the cupcakes right away. Store leftovers in an airtight container in the fridge for up to two days. Note that the meringue will not last much longer than a day.